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

[Alastair McKinstry]

Hi Jochen

Ok, the change is rolled back.

Ideally this is a non-invasive change - it just causes mod files to be 
created for both gfortran-11 and gfortran-12 but reality happens; it can 
wait.

Best regards

Alastair

On 21/06/2022 14:40, Jochen Sprickerhof wrote:
> 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
>
-- 
Alastair McKinstry,
GPG: 82383CE9165B347C787081A2CBE6BB4E5D9AD3A5
ph: +353 87 6847928 e: alastair at sceal.ie, im: @sceal.ie:mckinstry