Subject: Re: Sometimes the output to the stdout in Windows disappears
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Victor Spirin <v.spirin@postgrespro.ru>,
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From: Alexander Lakhin <exclusion@gmail.com>
Message-ID: <fca9beed-4902-d955-a691-96950fa54eaa@gmail.com>
Date: Sun, 18 Oct 2020 21:00:00 +0300
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17.10.2020 21:44, Tom Lane wrote:
> I propose the attached patch. If this doesn't cause buildfarm problems,
> perhaps we should back-patch it.
Thank you!
I've made a simple cmd script to reproduce problems seen on dory:
https://buildfarm.postgresql.org/cgi-bin/show_history.pl?nm=dory&br=HEAD

FOR /L %%I IN (1,1,200) DO call :CHECK %%I
GOTO :eof
:CHECK
echo iteration %1
call vcregress ecpgcheck
IF %ERRORLEVEL% NEQ 0 GOTO ERR
EXIT /B
:ERR
echo iteration %1 failed
pause

Without the fix I've got errors on iterations 43, 46, 128, 47, 14, 4,
27, which approximately corresponds to the ECPG-Check failure frequency
on dory (for HEAD).
With the fix all the 200 iterations passed as expected.
Then I ran the loop again just to be sure and got:
test thread/descriptor            ... stderr FAILED       81 ms
iteration 124 failed.

diff -w -U3
.../src/interfaces/ecpg/test/expected/thread-descriptor.stderr
.../src/interfaces/ecpg/test/results/thread-descriptor.stderr
--- .../src/interfaces/ecpg/test/expected/thread-descriptor.stderr   
2019-12-04 16:05:46 +0300
+++ .../src/interfaces/ecpg/test/results/thread-descriptor.stderr   
2020-10-18 20:20:27 +0300
@@ -0,0 +1 @@
+SQL error: descriptor "mydesc" not found on line 31

It's interesting that all failures before the fix were with stdout, but
this one is with stderr.
I'm going to investigate this issue further.

Best regards,
Alexander