Bug#1013316: early transition to gcc-12 breaks src:pcl on armhf/el

[Jochen Sprickerhof]

Package: dh-fortran-mod
Version: 0.23
Severity: normal

Hi Alastair,

could you revert the transition to gcc-12 for now and do it in parallel
with gcc switching to it by default?

Background:

src:pcl uses clang on armhf/el because it does not compile with gcc.
pcl build depends on libopenmpi-dev (through libvtk9-dev) and with this
libgcc-12-dev is pulled in (libopenmpi-dev -> gfortran-12 -> gcc-12 ->
libgcc-12-dev). But with libgcc-12-dev installed, clang expects to use
it and also needs libstdc++-12-dev which is not pulled in:

root at fenchel:/# echo "int main() {}" > broken.cpp
root at fenchel:/# clang++ broken.cpp
root at fenchel:/# apt install libgcc-12-dev
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
  libgcc-12-dev
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 2436 kB of archives.
After this operation, 14.6 MB of additional disk space will be used.
Get:1 http://deb.debian.org/debian unstable/main amd64 libgcc-12-dev amd64 12.1.0-4 [2436 kB]
Fetched 2436 kB in 3s (752 kB/s)
debconf: delaying package configuration, since apt-utils is not installed
Selecting previously unselected package libgcc-12-dev:amd64.
(Reading database ... 17811 files and directories currently installed.)
Preparing to unpack .../libgcc-12-dev_12.1.0-4_amd64.deb ...
Unpacking libgcc-12-dev:amd64 (12.1.0-4) ...
Setting up libgcc-12-dev:amd64 (12.1.0-4) ...
Processing triggers for ccache (4.6.1-1) ...
Updating symlinks in /usr/lib/ccache ...
root at fenchel:/# clang++ broken.cpp
/usr/bin/ld: cannot find -lstdc++: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)

As a result src:pcl currently fails to build on armhf/el. This is
unfortunate cause it blocks the onetbb transition. I talked to ginggs in
IRC and he proposed to revert the gcc-12 switch of dh-fortran-mod.

Cheers Jochen


-- System Information:
Debian Release: bookworm/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.18.0-2-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages dh-fortran-mod depends on:
ii  debhelper                   13.7.1
ii  gfortran-12                 12.1.0-4
ii  libfile-libmagic-perl       1.23-1+b2
ii  perl [libio-compress-perl]  5.34.0-4

dh-fortran-mod recommends no packages.

dh-fortran-mod suggests no packages.

-- no debconf information