@pytest.mark.skipif("sys.platform in ('win32', 'darwin')")
    def test_remove_dir_prefix(self):
        from _pytest._argcomplete import FastFilesCompleter
        ffc = FastFilesCompleter()
        fc = FilesCompleter()
        for x in '/usr/'.split():
            assert not equal_with_bash(x, ffc, fc, out=py.std.sys.stdout)
this is not compatible with compgen but it is with bash itself:
dataset/ETHPy150Open pytest-dev/pytest/testing/test_argcomplete.py/TestArgComplete.test_remove_dir_prefix