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[PATCH v44 02/10] Do not dereference varattrib_4b in VARSIZE_4B.
266+ messages / 2 participants
[nested] [flat]

* [PATCH v44 02/10] Do not dereference varattrib_4b in VARSIZE_4B.
@ 2026-03-11 13:53  Antonin Houska <ah@cybertec.at>
  0 siblings, 0 replies; 266+ messages in thread

From: Antonin Houska @ 2026-03-11 13:53 UTC (permalink / raw)

Since VARSIZE_ANY() may call VARSIZE_4B(), it's possible that the compiler
(when invoked with -Warray-bounds) complains if the argument of VARSIZE_ANY()
is actually smaller than what VARSIZE_4B() expects. This patch adjusts the
VARSIZE_4B() macro so that it does not have to dereference the varattrib_4b
structure. We assume that varlena value always starts with the length word.

The problem does not exist in the tree at the moment since the current users
of VARSIZE_ANY() pass a pointer to a dynamically allocated memory, so the
compiler has no idea about the memory available. However, in an upcoming
patch, it makes sense to pass a pointer to a local variable of "varlena"
type. In such a case, the compiler warning might appear because
sizeof(varlena) is lower than sizeof(varattrib_4b).
---
 src/include/varatt.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/include/varatt.h b/src/include/varatt.h
index 000bdf33b92..31063e5d4f1 100644
--- a/src/include/varatt.h
+++ b/src/include/varatt.h
@@ -207,7 +207,7 @@ typedef struct
 
 /* VARSIZE_4B() should only be used on known-aligned data */
 #define VARSIZE_4B(PTR) \
-	(((const varattrib_4b *) (PTR))->va_4byte.va_header & 0x3FFFFFFF)
+	(*((const uint32 *) (PTR)) & 0x3FFFFFFF)
 #define VARSIZE_1B(PTR) \
 	(((const varattrib_1b *) (PTR))->va_header & 0x7F)
 #define VARTAG_1B_E(PTR) \
@@ -240,7 +240,7 @@ typedef struct
 
 /* VARSIZE_4B() should only be used on known-aligned data */
 #define VARSIZE_4B(PTR) \
-	((((const varattrib_4b *) (PTR))->va_4byte.va_header >> 2) & 0x3FFFFFFF)
+	((*((const uint32 *) (PTR)) >> 2) & 0x3FFFFFFF)
 #define VARSIZE_1B(PTR) \
 	((((const varattrib_1b *) (PTR))->va_header >> 1) & 0x7F)
 #define VARTAG_1B_E(PTR) \
-- 
2.47.3


--gwom7bl7ogtszo4k
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment;
	filename="v44-0003-Add-CONCURRENTLY-option-to-REPACK-command.patch"



^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread

* [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc
@ 2026-07-15 19:27  Andres Freund <andres@anarazel.de>
  0 siblings, 0 replies; 266+ messages in thread

From: Andres Freund @ 2026-07-15 19:27 UTC (permalink / raw)

Unfortunately the combination of gcc, precompiled headers, ccache and meson
currently is not safe without further options. The dependencies emitted by gcc
are insufficient to trigger rebuilds when headers "below" the precompiled
headers are changed. Whether that's a ccache, gcc or meson bug is
debatable. Luckily gcc's -fpch-deps option fixes the issue.

This problem occasionally leads to build failures, e.g. if only c.h,
postgres.h or pg_config_manual.h change. That's e.g. the case when creating a
new major version branch.

Discussion: https://postgr.es/m/CAN55FZ0tqR6Xz%3DiVFLc1BBoLOEHU775ARhcGYwggHA3XLA%3DoQg%40mail.gmail.com
Discussion: https://postgr.es/m/CA+hUKG+s7Yvt0PUnSQUEjCjysV-7-51n9B1h468Le3VJi0x4ZQ@mail.gmail.com
Discussion: https://postgr.es/m/phsrssp75npoyalqsolcd7fmnmlbzbmquc2p7w7mqjlw7432jk@bzskz3luyjvb
Discussion: https://github.com/ccache/ccache/issues/1686
Backpatch-through: 16, where meson support was added
---
 meson.build | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meson.build b/meson.build
index 61b5681851e..f4cde249242 100644
--- a/meson.build
+++ b/meson.build
@@ -2185,6 +2185,12 @@ common_functional_flags = [
   # Disable optimizations that assume no overflow; needed for gcc 4.3+
   '-fwrapv',
   '-fexcess-precision=standard',
+  # Without -fpch-deps gcc emits dependencies that are insufficient for ccache
+  # to trigger a rebuild when the precompiled header changes. We could make
+  # this depend on using gcc and precompiled headers being enabled, but that's
+  # probably not worth it.  See also
+  # https://github.com/ccache/ccache/issues/1686
+  '-fpch-deps',
 ]
 
 cflags += cc.get_supported_arguments(common_functional_flags)
-- 
2.54.0.450.g9ac3f193c0


--lrkjybh77g2jf2vx--





^ permalink  raw  reply  [nested|flat] 266+ messages in thread


end of thread, other threads:[~2026-07-15 19:27 UTC | newest]

Thread overview: 266+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2026-03-11 13:53 [PATCH v44 02/10] Do not dereference varattrib_4b in VARSIZE_4B. Antonin Houska <ah@cybertec.at>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>
2026-07-15 19:27 [PATCH v2] meson: Fix ccache issues when using precompiled headers with gcc Andres Freund <andres@anarazel.de>

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