CI: stop validating GHC 7

[andreasabel]

Changes:

• bump GHC_FOR_RELEASE to 9.4.8
• bump action versions
• uniform quoting style
• satisfy actionlint
• fix order: setup Haskell before cache restore (uses setup.haskell-outputs)
• use --ignore-project in cabal install hackage-repo-tool
• closes cabal-testsuite fails early on with linker error on Windows since GHC 9.6 #8858: deleted comment
• closes CI validate-old-ghcs broken after haskell-actions/setup upgraded to node20 #9858 by dropping container and use ghcup to setup ghcs

[andreasabel]

Need to investigate https://github.com/haskell/cabal/actions/runs/8657545162/job/23739898187?pr=9886#step:9:93

PackageTests/ForeignLibs/setup.test.hs FAIL (unexpected success) (2.81s)

https://github.com/haskell/cabal/blob/master/cabal-testsuite/PackageTests/ForeignLibs/setup.test.hs
Code links to:

• unrelated: GHC 9.4 Windows regressions in test suite #8451
• related: CI updates (drop 8.4.4, update old-ghcs, update bootstrap plans) #9722

The latter marks this test broken in a90d44f but without investigation or justification, so I'll try just reverting this commit.

[andreasabel]

Installing GHC 7.10.3 with ghcup maybe does not work (anymore?): https://github.com/haskell/cabal/actions/runs/8657642919/job/23740165824?pr=9886#step:5:236

Installing library in
/usr/local/.ghcup/tmp/ghcup-24d6e4618d6fbdde/usr/local/.ghcup/ghc/7.10.3/lib/ghc-7.10.3/ghcpr_8TmvWUcS1U1IKHT0levwg3
gmake[1]: *** [ghc.mk:924: install_packages] Segmentation fault (core dumped)

Segmentation fault? Congratulations!

Possibly a follow-up error: https://github.com/haskell/cabal/actions/runs/8657642919/job/23740165824?pr=9886#step:5:253

Error: Process "gmake" with arguments ["DESTDIR=/usr/local/.ghcup/tmp/ghcup-24d6e4618d6fbdde", "install"] failed with exit code 2.

P.S.: My former self knew about this problem: haskell-actions/setup@c44725f
For validating GHC 7.10 we would need ubuntu-20.04, so I am dropping GHC 7.10.3 for now.

Our GHC support window seems to be 5 years:

cabal/CONTRIBUTING.md

Lines 194 to 205 in 8e971f5

	* Our GHC support window is five years for the Cabal library and three
	years for cabal-install: that is, the Cabal library must be
	buildable out-of-the-box with the dependencies that shipped with GHC
	for at least five years. GitHub Actions checks this, so most
	developers submit a PR to see if their code works on all these
	versions of GHC. `cabal-install` must also be buildable on all
	supported GHCs, although it does not have to be buildable
	out-of-the-box. Instead, the `cabal-install/bootstrap.sh` script
	must be able to download and install all of the dependencies (this
	is also checked by CI). Also, self-upgrade to the latest version
	(i.e. `cabal install cabal-install`) must work with all versions of
	`cabal-install` released during the last three years.

There is a discussion here:

• Create a new document about support policies in readthedocs #8108 (comment)

[andreasabel]

https://github.com/haskell/cabal/actions/runs/8658240648/job/23741747126?pr=9886#step:19:388

UNEXPECTED FAIL: PackageTests/NewBuild/CmdRun/Terminate/cabal.test.hs

https://github.com/haskell/cabal/actions/runs/8658240648/job/23741747126?pr=9886#step:19:336

PackageTests/NewBuild/CmdRun/Terminate/cabal.test.hs FAIL (16.32s)
...
08:03:59.076216000000 [cabal.test] about to terminate cabal
08:03:59.058669000000 [exe ] about to write file
08:03:59.059507000000 [exe ] about to sleep
08:04:09.158424000000 [exe ] done sleeping
08:04:09.158488000000 [exe ] exiting
cabal: waitForProcess: does not exist (No child processes)
terminated
08:04:09.186228000000 [cabal.test] v2-run done
*** Exception: unexpected: done sleeping

Is this a race?

Former self says yes:

• PackageTests/NewBuild/CmdRun/Terminate brittle, may fail on CI #8416

[andreasabel]

Yay, Ci passed!

[ulysses4ever]

Terrific, thank you!

we really need a definitive place where we list our GHC support windows for different modes (compiling with vs driving). Otherwise it’s a unnecessary stress to approve prs removing support for older ghc, which we have to do regularly.

[Mikolaj]

A bit late in the release process, but a backport may save us a CI interruption on branch 3.12 soon. Or we may backport or merge the backport after the release is done?

[Mikolaj]

To be backported after 3.12.0.0 is out.

[Mikolaj]

@mergify backport 3.12

[mergify]

backport 3.12

✅ Backports have been created

• #9957 CI: stop validating GHC 7 (backport #9886) has been created for branch 3.12 but encountered conflicts