FileList.files order discrepancy on Arch Linux since 28.5.0

[felixonmars]

Reproduced in both Python 2.7.12 and 3.5.2. I have tried both ptr and tox and still getting the same test failure:

=================================== FAILURES ===================================
____________________ TestFileListTest.test_include_pattern _____________________

self = <setuptools.tests.test_manifest.TestFileListTest object at 0x7fe946df4860>

    def test_include_pattern(self):
        # return False if no match
        file_list = FileList()
        self.make_files([])
        assert not file_list.include_pattern('*.py')

        # return True if files match
        file_list = FileList()
        self.make_files(['a.py', 'b.txt'])
        assert file_list.include_pattern('*.py')

        # test * matches all files
        file_list = FileList()
        self.make_files(['a.py', 'b.txt'])
        file_list.include_pattern('*')
>       assert file_list.files == ['a.py', 'b.txt']
E       assert ['b.txt', 'a.py'] == ['a.py', 'b.txt']
E         At index 0 diff: 'b.txt' != 'a.py'
E         Use -v to get the full diff

[jaraco]

Any idea why the tests pass on Travis? Is it perhaps an intermittent failure?

[felixonmars]

No idea yet. I have tried to play with PYTHONHASHSEED and got not difference. It is still 100% reproducible on all three of my Arch Linux x86_64 machines.

[jaraco]

Probably implicated is #764. @timheap Can you assist?

[mx-moth]

Different OSs and file systems do not always list files in creation order it appears, so the tests fail on some systems. I've added a file_list.sort() before each assertion in the tests to ensure a consistent order, over in #818