macOS wheel builds broken because of find_sources test failure

[JukkaL]

macOS wheel builds are broken because of a test failure:

...
        files = {
            "pkg/a1/b/c/d/e.py",
            "pkg/a1/b/f.py",
            "pkg/a2/__init__.py",
            "pkg/a2/b/c/d/e.py",
            "pkg/a2/b/f.py",
        }
        fscache = FakeFSCache(files)
>       assert len(find_sources(["/"], options, fscache)) == len(files)

site-packages/mypy/test/test_find_sources.py:363: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
site-packages/mypy/test/test_find_sources.py:59: in find_sources
    return normalise_build_source_list(create_source_list(paths, options, fscache))
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   mypy.find_sources.InvalidSourceList: There are no .py[i] files in directory '/'

This is blocking the 0.810 release #10062.

[JukkaL]

Actually it's unclear if this is failing on the 0.810 release branch. If it's only failing on master, this doesn't block the 0.810 release.

[JukkaL]

Yes, this is failing on the 0.810 release branch, as I feared originally. I'm working on a fix.

[JukkaL]

The wheel build is still failing. I have another attempt being built, but at least if it doesn't work, I'll probably have to postpone until the next week.

[hauntsaninja]

Sorry for the trouble, I'm optimistic #10077 would fix.

[hauntsaninja]

Your fix seems to have worked... But maybe we should change the logic a little:

mypy/mypy/modulefinder.py

Line 479 in 6bfc2db

subpath_str = os.path.abspath(subpath).replace(os.sep, "/")

We currently normalise the path for the purposes of --exclude using abspath, but maybe we should use relpath. This would make the behaviour more consistent across possible project locations (assuming that you run mypy from within the project)

[hauntsaninja]

I opened a PR in case you think using relpath is better: #10078

[JukkaL]

@hauntsaninja Thanks, the macOS wheel builds work now.