gnupg2 uses the libgpg-error library. The libgpg-error library has a
long plan to be renamed to "gpgrt" (see [1]). For the transition, it
provides two configuration scripts "gpg-error-config" (the old,
original one, kept for compatibility) and "gpgrt-config" (which is
meant to be the replacement). When both are detected, "gpgrt-config"
should be preferred.
gnupg2 configure script searches for "gpg-error-config" in the path
provided to --with-libgpg-error-prefix=PFX (more specifically, in
"PFX/bin").
The logic to find "gpgrt-config" is different: it is searched in
paths "$prefix/bin:$PATH". See [2]. On Buildroot, autotools target
packages are configured with "--prefix=/usr", which makes the
configure script to search in the host "/usr/bin".
In some host environment providing such a "/usr/bin/gpgrt-config"
script of an older version, host compilation flags are incorrectly
added for the target, which leads to compilation failures.
The issue can be reproduced in a Buildroot Docker image from [3] in
which the libgpg-error-dev package is added. When tested, the
libgpg-error-dev package was at version 1.38.
In that configuration, gnupg2 configure will output the message:
checking for gpgrt-config... /usr/bin/gpgrt-config
and the compilation fails with a message:
aarch64-buildroot-linux-gnu-gcc: ERROR: unsafe header/library path used in cross-compilation: '-I/usr/include'
Note: it was observed that in some other configurations in which the
host /usr/bin/gpgrt-config was from libgpg-error version 1.46, the
host script was redirecting correctly in the buildroot sysroot.
Since gnupg2 searches for "gpgrt-config" with a
"AC_PATH_PROG(GPGRT_CONFIG, ...)" macro, this patch fixes this
issue by simply forcing the script path in the GPGRT_CONFIG
environment variable.
See also [4] which discussed the "gpgrt-config" search logic.
Fixes:
- http://autobuild.buildroot.net/results/423c3ce7317c181e9f2e4a49b76ee9d26167375c/
(and many others)
[1] https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgpg-error.git;a=blob;f=README;h=e0b9f16445a96942af0839bcdb9a0b0f8cf31380;hb=885a287a57cf060b4c5b441822c09d23b8dee2bd#l29
[2] https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=blob;f=m4/gpg-error.m4;h=a975e53d07d1b743f51d8aa1767cd8e0d71b4071;hb=c0556edb80518720b0d884251685fe008c8f0429#l68
[3] https://git.buildroot.org/buildroot/tree/support/docker/Dockerfile?id=b6085c00d0feece6f3ba635e7847ea653bc5fac3
[4] https://dev.gnupg.org/T5365
Reported-by: Bagas Sanjaya <bagasdotme@gmail.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
d7f2d8403e