Index: Lib/test/test_os.py =================================================================== --- Lib/test/test_os.py (revision 74154) +++ Lib/test/test_os.py (working copy) @@ -617,7 +617,16 @@ def test_closerange(self): if hasattr(os, "closerange"): fd = support.make_bad_fd() - self.assertEqual(os.closerange(fd, fd + 10), None) + for i in range(10): + try: os.fstat(fd+i) + except OSError: + pass + else: + break + if i < 2: + raise unittest.SkipTest( + "Unable to acquire a range of invalid file descriptors") + self.assertEqual(os.closerange(fd, fd + i-1), None) def test_dup2(self): if hasattr(os, "dup2"):