Bug#868013: Fwd: Re: gcc7 transition and dh_fortran

[Alastair McKinstry]

Dear Jakub,

I'm contacting you as you would probably know best who is responsible
for gfortran in Redhat and know who best to contact amongst the gcc
upstream.

I'm working on a helper package for Debian packaging of Fortran
libraries; it tracks .mod files and their versions. The primary aim is
to track when we need to rebuild due to gfortran transitions (mod format
changes), but there is a also a related issue due to other compilers,
such as the new flang compiler.

That is, mod files from different compilers and versions are
incompatible. At the moment we place these in Debian in /usr/include,
but this is impossible if we have two incompatible fortran compilers
(gfortran and flang).

I am proposing that we use /usr/include/fortran/$compiler/$version

For different compiler versions, and that this path be automatically
searched by the compiler.

I see a similar discussion here:

https://bugzilla.redhat.com/show_bug.cgi?id=1192617

Are you aware of any conclusions or similar proposals? who do you think
I should be contacting ?

best regards

Alastair McKinstry




-------- Forwarded Message --------
Subject: Re: gcc7 transition and dh_fortran
Resent-Date: Tue, 25 Jul 2017 06:21:59 +0000 (UTC)
Resent-From: debian-***@lists.debian.org
Date: Tue, 25 Jul 2017 07:21:27 +0100
From: Alastair McKinstry <***@debian.org>
Organisation: Debian

Hi,
We will be transitioning to gcc7 soon for Buster, and with it there is
another Fortran transition. This is because the format for gfortrans mod
files has changed again.

did it? At least the fortran module version is the same upstream (14).
However the libgfortran soname was bumped from 3 to 4, so we will have a
transition / rebuild cycle anyway.

Yes. I had thought that the transition involved a mod file change; it
doesn't but there is a transition needed.

Should compilers be set to check a subdirectory of /usr/include to look
for .mod files suitable for their use?
I haven't looked into that, however if compiler patches would be required then
please discuss these with upstream first.

Agreed.
I see that there is some similar work proposed on Redhat /Fedora at least:
https://bugzilla.redhat.com/show_bug.cgi?id=1192617
https://fedoraproject.org/wiki/Packaging:Fortran
https://www.redhat.com/archives/fedora-packaging/2007-October/msg00011.html

I will try to co-ordinate with them

Matthias

Alastair