libgcrypt: detect libgpg-error with pkg-config

[Vincent Torri]

On Sun, May 3, 2026 at 1:14 PM Andreas Metzler <ametzler at bebt.de> wrote:
>
> On 2026-05-03 Niibe Yutaka <gniibe at fsij.org> wrote:
> > Vincent Torri wrote:
> > > and about using pkg-config instead to detect libgpg-error ?
>
> > The configure script of libgcrypt is written for use of gpgrt-config.
> > It's same for other libraries of GnuPG, and GnuPG itself.
>
> > gpgrt-config is developed to replace many *-config for GnuPG
> > (gpg-error-config, libgcrypt-config, libassuan-config, libksba-config,
> > and npth-config, etc.).  gpgrt-config is a minimum subset of pkg-config.
> > "Minimum" means that, it should have enough but no other features to
> > support GnuPG build.
>
> > The intention is to allow building GnuPG without pkg-config.  GnuPG
> > build could be done in an early stage of OS porting, so, we pursue
> > less dependency other than GNU toolchain.
>
> > True, technically, it is possible to modify those configure scripts
> > to use pkg-config instead of gpgrt-config.  But our intention is
> > use of gpgrt-config here.
>
> > We (GnuPG team) don't have any plan to modify those configure scripts
> > with pkg-config
>
> Hello,
>
> well nowadays everybody is using pkgconf instead of the original
> pkg-config implementation. pkg-config depended on glib but pkgconf
> basically only needs a C-compiler and is therefore very easy to
> bootstrap.
>
> >From a user's point of view the biggest downside of the
> gpgrt-config-using autoconf tests is their lack of speed:
>
> Compare running minimal configure.ac with
>  PKG_CHECK_MODULES([GPGERROR], [gpg-error >= 1.0] ) ...
>
> (sid)ametzler at argenau:/tmp/HELLO$ time ./configure
> [...]
> checking for pkg-config... /usr/bin/pkg-config
> checking pkg-config is at least version 0.9.0... yes
> checking for gpg-error >= 1.0 ... yes
> configure: creating ./config.status
>
> real    0m0.372s
> user    0m0.276s
> sys     0m0.107s
>
> ... OTOH with AM_PATH_GPG_ERROR([1.0])
> checking build system type... x86_64-pc-linux-gnu
> checking host system type... x86_64-pc-linux-gnu
> checking for gpg-error-config... no
> checking for gpgrt-config... /usr/bin/gpgrt-config
> configure: Use gpgrt-config with /usr/lib/x86_64-linux-gnu as gpg-error-config
> checking for GPG Error - version >= 1.0... yes (1.59)
> configure: creating ./config.status
>
> real    0m2.236s
> user    0m1.671s
> sys     0m0.737s
>

if you want speed, use a meson build system using muon (C port of
meson) instead of autotools...

Vincent Torri