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Message-ID: <9c051556-cbb6-4909-a4af-e79c3572a91e@eisentraut.org>
Date: Tue, 13 Aug 2024 22:13:27 +0200
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Subject: Re: Improve error message for ICU libraries if pkg-config is absent
To: Heikki Linnakangas <hlinnaka@iki.fi>, Michael Banck <mbanck@gmx.net>,
 PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Cc: Holger Jakobs <holger@jakobs.com>
References: <66b5d05c.050a0220.7c8ce.a951@mx.google.com>
 <b0523547-4222-4838-869a-aaa0e9fe53ab@iki.fi>
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From: Peter Eisentraut <peter@eisentraut.org>
In-Reply-To: <b0523547-4222-4838-869a-aaa0e9fe53ab@iki.fi>
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On 09.08.24 10:59, Heikki Linnakangas wrote:
> On 09/08/2024 11:16, Michael Banck wrote:
>> Hi,
>>
>> Holger Jacobs complained in pgsql-admin that in v17, if you have the ICU
>> development libraries installed but not pkg-config, you get a somewhat
>> unhelpful error message about ICU not being present:
>>
>> |checking for pkg-config... no
>> |checking whether to build with ICU support... yes
>> |checking for icu-uc icu-i18n... no
>> |configure: error: ICU library not found
>> |If you have ICU already installed, see config.log for details on the
>> |failure.  It is possible the compiler isn't looking in the proper 
>> directory.
>> |Use --without-icu to disable ICU support.
>>
>> The attached patch improves things to that:
>>
>> |checking for pkg-config... no
>> |checking whether to build with ICU support... yes
>> |configure: error: ICU library not found
>> |The ICU library could not be found because pkg-config is not 
>> available, see
>> |config.log for details on the failure.  If ICU is installed, the 
>> variables
>> |ICU_CFLAGS and ICU_LIBS can be set explicitly in this case, or use
>> |--without-icu to disable ICU support.
> 
> Hmm, if that's a good change, shouldn't we do it for all libraries that 
> we try to find with pkg-config?
> 
> I'm surprised the pkg.m4 module doesn't provide a nice error message 
> already if pkg-config is not found. I can see some messages like that in 
> pkg.m4. Why are they not printed?

Because we override it with our own message.  If we don't supply our own 
message, we get the built-in ones.  Might be worth trying whether the 
built-in ones are better?  (But they won't know about higher-level 
options like "--without-icu", so they won't be able to give suggestions 
like that.)