Compile failure / inaccurate version bounds

[hvr]

The release declares

  build-depends:     base >= 4 && <5

However, GHC 7.8 and GHC 7.6 disagree:

Configuring component lib from path-0.5.11
Preprocessing library path-0.5.11...
[1 of 2] Compiling Path.Internal    ( src/Path/Internal.hs, /tmp/matrix-worker/1481029286/dist-newstyle/build/x86_64-linux/ghc-7.8.4/path-0.5.11/build/Path/Internal.o )
[2 of 2] Compiling Path             ( src/Path.hs, /tmp/matrix-worker/1481029286/dist-newstyle/build/x86_64-linux/ghc-7.8.4/path-0.5.11/build/Path.o )

src/Path.hs:415:10:
    Could not deduce (Functor m) arising from a use of ‘fmap’
    from the context (MonadThrow m)
      bound by the type signature for
                 setFileExtension :: MonadThrow m =>
                                     String -> Path b File -> m (Path b File)
      at src/Path.hs:(409,21)-(412,20)
    Possible fix:
      add (Functor m) to the context of
        the type signature for
          setFileExtension :: MonadThrow m =>
                              String -> Path b File -> m (Path b File)
    In the expression:
      fmap coerce (parseAbsFile (FilePath.replaceExtension path ext))
    In the expression:
      if FilePath.isAbsolute path then
          fmap coerce (parseAbsFile (FilePath.replaceExtension path ext))
      else
          fmap coerce (parseRelFile (FilePath.replaceExtension path ext))
    In an equation for ‘setFileExtension’:
        setFileExtension ext (Path path)
          = if FilePath.isAbsolute path then
                fmap coerce (parseAbsFile (FilePath.replaceExtension path ext))
            else
                fmap coerce (parseRelFile (FilePath.replaceExtension path ext))

Configuring component lib from path-0.5.11
Preprocessing library path-0.5.11...

src/Path.hs:59:18:
    Could not find module `Data.Coerce'
    Use -v to see a list of the files searched for.

[mrkkrp]

Yep, I'm now deciding wether to drop path as a dependency or drop support for older GHCs for one project. CI could help here to ensure that the package builds OK with all GHC versions.

Edit: Ah no, wrong, path has CI enabled and it passes for 7.6, but still the library fails to build for me and @hvr...