Hum, the test also fails on Mac OS X Tiger:

http://buildbot.python.org/all/builders/x86%20Tiger%202.7/builds/2944/steps/test/logs/stdio



======================================================================
FAIL: test_urandom_fd_non_inheritable (test.test_os.URandomTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/db3l/buildarea/2.7.bolen-tiger/build/Lib/test/test_os.py", line 597, in test_urandom_fd_non_inheritable
    self.assertEqual(open_fds - set(range(3)), set())
AssertionError: Items in the first set but not the second:
5


Why do we still maintain these old operating systems? :-p