Add MHS as a recognized compiler.

[augustss]

The title says it all.

[geekosaur]

Does this need additional code for compiler support? (cf. Distribution.Simple.{GHC,HaskellSuite,…})

[augustss]

I don't care about additional code right now. I just want to have mhs be recognized as a valid Haskell compiler to be used in .cabal files.

To build things with mhs I use mcabal anyway.

[geekosaur]

Looks like a hash needs to be updated:

  Distribution.Utils.Structured
    GenericPackageDescription:                                           FAIL (0.02s)
      tests/UnitTests/Distribution/Utils/Structured.hs:31:
      expected: 5a48c6570cbcf96af4c51f38962e37b5
       but got: f6306d42af1d4f88b269cbd6a7879e6d
      Use -p '/Distribution.Utils.Structured.GenericPackageDescription/' to rerun this test only.
    LocalBuildInfo:                                                      FAIL (0.02s)
      tests/UnitTests/Distribution/Utils/Structured.hs:31:
      expected: 6d668de33d7b4d5df3830e65e6941373
       but got: 214d441d7d9bf881624984de13980b37
      Use -p '/LocalBuildInfo/' to rerun this test only.

[Mikolaj]

Let me rebase to verify CI passes after we worked around the github changes breakage.

[Mikolaj]

@mergify rebase

[mergify]

rebase

✅ Branch has been successfully rebased

[Mikolaj]

Actually, @geekosaur was right all along --- the hashes need to be updated to the ones given in https://github.com/haskell/cabal/actions/runs/8908155162/job/24463289224?pr=9878. @augustss: I'm afraid that's the task of the PR author. We'd also need a tiny changelog file: https://github.com/haskell/cabal/blob/master/CONTRIBUTING.md#changelog. I think, we can skip a test in this case, but it never hurts to add one. Thank you for the PR!