Bug#1109071: libgcrypt20 FTBFS with gcc-15

[Andreas Metzler]

On 2025-07-10 Helmut Grohne <helmut at subdivi.de> wrote:
> Source: libgcrypt20
> Version: 1.11.0-7
> Severity: important
> Tags: ftbfs forky sid
> User: helmutg at debian.org
> Usertags: rebootstrap

> Hi,

> libgcrypt20 fails to build from source with gcc-15 for some 
> architectures. The cause may be found in mpi/longlong.h. In several 
> lines such as 193, 499 and 1409, there are function prototypes without 
> arguments. This trips up the updated language standard by gcc-15 and 
> building libcrypt20 now complains about excess arguments. For example:

> | In file included from ../../mpi/mpih-div.c:32:
> | ../../mpi/mpih-div.c: In function ‘_gcry_mpih_mod_1’:
> | ../../mpi/longlong.h:190:11: error: too many arguments to function ‘__udiv_qrnnd’; expected 0, have 4
> |   190 |     (q) = __udiv_qrnnd (&__r, (n1), (n0), (d));                         \
> |       |           ^~~~~~~~~~~~  ~~~~
> | ../../mpi/mpih-div.c:84:17: note: in expansion of macro ‘udiv_qrnnd’
> |    84 |                 udiv_qrnnd(divisor_limb_inverted, dummy,
> |       |                 ^~~~~~~~~~
> | ../../mpi/longlong.h:193:16: note: declared here

> This does not seem to affect amd64 as Matthias would have otherwise 
> reported this problem already. It does affect at least alpha.

It also does not show up on mips64el and arm64.

powerpc64le shows a
different issue, it fails late without earlier warnings:
libtool: link: ( cd ".libs" && rm -f "libgcrypt.la" && ln -s "../libgcrypt.la" "libgcrypt.la" )
/bin/bash ../libtool  --tag=CC   --mode=link gcc-15  -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/home/ametzler/GCR/libgcrypt20-1.11.1=. -fstack-protector-strong -Wformat -Werror=format-security -fvisibility=hidden -fno-delete-null-pointer-checks -Wall  -Wl,-z,relro -Wl,-z,now -o mpicalc mpicalc-mpicalc.o libgcrypt.la -L/usr/lib/powerpc64le-linux-gnu -lgpg-error
libtool: link: gcc-15 -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/home/ametzler/GCR/libgcrypt20-1.11.1=. -fstack-protector-strong -Wformat -Werror=format-security -fvisibility=hidden -fno-delete-null-pointer-checks -Wall -Wl,-z -Wl,relro -Wl,-z -Wl,now -o .libs/mpicalc mpicalc-mpicalc.o  ./.libs/libgcrypt.so -L/usr/lib/powerpc64le-linux-gnu -lgpg-error
/usr/bin/ld: ./.libs/libgcrypt.so: undefined reference to `gcry_poly1305_p10le_4blocks'
/usr/bin/ld: ./.libs/libgcrypt.so: undefined reference to `_gcry_chacha20_p10le_8x'
collect2: error: ld returned 1 exit status
make[3]: *** [Makefile:662: mpicalc] Error 1
make[3]: Leaving directory '/home/ametzler/GCR/libgcrypt20-1.11.1/build/src'

We do not have an alpha Developer Machine account anymore. Any idea
where else this should show up?

cu Andreas