Append paths in global config to progdb in configureCompiler

[jasagredo]

Closes #9800

---

Template Α: This PR modifies behaviour or interface

Include the following checklist in your PR:

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
  • Is the change significant? If so, remember to add significance: significant in the changelog file.
• The documentation has been updated, if necessary.
• Manual QA notes have been included.
• Tests have been added. (Ask for help if you don’t know how to write them! Ask for an exemption if tests are too complex for too little coverage!)

[Mikolaj]

Thank you! Would it be possible to add a test for this?

[mpickering]

Could you perhaps add a testcase? See the similar test I added in 2c19bf3

[jasagredo]

I think a test would be possible to add. I however don't have the time at the moment for doing cabal stuff in my free time.

[yutotakano]

I feel like I can contribute the test case.

I just want some clarification from Cabal devs beforehand though: The ExtraProgPath test seems to cover this scenario already (a global/project-level pkg-config override). Indeed, that test fails on my Mac before the PR, and passes with this PR. Is this correct behaviour? It's apparently skipped in the CI since it depends on cabal-install. I just wanted to check with someone else since I found it weird that an existing test fails with existing code.

The modification I would make to the test case is to make it cover Windows as well, which should cover the specific case raised in #9800 and probably would close #6304.

[mpickering]

I think it probably isn't skipped on CI, it's probably one which you have to pass --with-cabal to. I will look at what the testcase does tomorrow to comment more precisely.

[jasagredo]

If I recall correctly it is indeed skipped on CI on Windows because "Windows CI has no pkg-config". So probably if you make sure pkg-config is installed before starting the testsuite you might be able to not skip it and call it a day.

I do wonder why I chose to skip it always on Windows and not only on Windows+CI 🤔

[jasagredo]

If you look at this CI run, https://github.com/haskell/cabal/actions/runs/13251642775/job/36994558671#step:17:1 for MacOS in a PR separate from this one, and search for "ExtraProgPath/" you will see it is mentioned twice.

The first time it is a Cabal-the-library testsuite so it is skipped, and the second time it is a cabal-the-tool (cabal-install) testsuite. The second time it is run and the test is successful.

What error does it show in your Mac?

(Note you can filter the tests run with -p "/ExtraProgPath/" iirc)

(Also many thanks for offering to add the test)

[Kleidukos]

Three primes muddy the waters a bit much here. Could you rename those progdb bindings to something more meaningful?

[yutotakano]

If you look at this CI run, haskell/cabal/actions/runs/13251642775/job/36994558671#step:17:1 for MacOS in a PR separate from this one, and search for "ExtraProgPath/" you will see it is mentioned twice.

You're right, the tests do actually pass already. I was incorrectly comparing my local version (3.12.0.0) with the post-PR build of cabal-install when I should've been comparing a build pre-PR and post-PR.

I'll write up the tests for the global progdb soon, likely as a new test called ExtraProgPathGlobal. I can't seem to find another test that creates and uses a global cabal config though, so if you have any quick pointers on how to mock that, it would be great. Otherwise, I'll take a stab during the weekend.

[yutotakano]

@jasagredo Could you please enable edit access on the PR? There should be a tickbox on the sidebar. I've written the test and fixed the triple primes but can't push. Unless it's better making another PR?

[jasagredo]

I can't do it because the GitHub app doesn't have that option :( . I will have access to a computer on Wednesday, otherwise feel free to open another PR and close this one as superseded.