Re: Improve error message for ICU libraries if pkg-config is absent

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?

> Also, this should be backpatched to v17 if accepted.
Did something change here in v17?

-- 
Heikki Linnakangas
Neon (https://neon.tech)