Drop support for optional packages with system gcc 4.x on ubuntu-trusty, debian-jessie, linuxmint-17, centos-7

[mkoeppe]

ubuntu-trusty 14.04 is long past "standard support" and will reach its EOL in April 2022 (https://wiki.ubuntu.com/Releases), but several optional packages do not build on it because of an outdated compiler (gcc 4.x)

debian-jessie (8) is past EOL LTS, with EOL ELTS in June 2022 (https://wiki.debian.org/DebianReleases). Same situation with gcc 4.x.

linuxmint-17 is past EOL (https://forums.linuxmint.com/viewtopic.php?t=289281). gcc 4.x

centos-7 has EOL June 2024. gcc 4.x

We switch these systems in the GH Actions CI tests for optional packages to using the gcc_spkg configuration factor.

Next wave:

• linuxmint-18 with gcc 5.4
• slackware-14.2 with gcc 5.5

Depends on #29527

CC: @kliem @dimpase

Component: porting

Author: Matthias Koeppe

Branch/Commit: 17ca365

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/31526

[mkoeppe]

Dependencies: #29527

[mkoeppe]

Branch: u/mkoeppe/drop_support_for_optional_packages_on_ubuntu_trusty__debian_jessie__linuxmint_17__centos_7

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Commit: 85a4449

[mkoeppe]

New commits:

a1be70b	tox.ini: Add opensuse-15.3
9708864	.github/workflows/tox*.yml: Add opensuse
ccb0d71	Merge #29527
85a4449	.github/workflows/tox-{optional,experimental}.yml: Remove test of distributions with gcc 4.x

[kliem]

comment:5

It's a bit bad for the centos-7 that still is far from EOL.

What's the recommended way around for users on this? -without-system-gcc? Can we test this?

[kliem]

comment:6

Then again from what I see the tox-gcc_spkg.yml run is far from stable, so perhaps we do not gain anything by adding it.

[mkoeppe]

comment:7

Yes, trying to fix up some gcc_spkg builds (on top of #29703), and then testing optional packages with that could be a possible strategy.

Perhaps we should also add a configure warning if we encounter ancient system gccs, advising users to upgrade their system or at least their toolchain (related: #27853)

[sagetrac-git]

Changed commit from 85a4449 to 17ca365

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

17ca365

.github/workflows/tox-{optional,experimental}.yml: Switch distributions with gcc 4.x to using gcc_spkg

[dimpase]

comment:12

lgtm

[mkoeppe]

comment:13

Thanks!

[mkoeppe]

Reviewer: Dima Pasechnik

[vbraun]

Changed branch from u/mkoeppe/drop_support_for_optional_packages_on_ubuntu_trusty__debian_jessie__linuxmint_17__centos_7 to 17ca365