While building 2.5rc1 under MacOS 10.4.7, one of the ctypes module 
unit tests fails:

% ./python.exe -V
Python 2.5c1 (r25c1:51426, Aug 21 2006, 11:30:05) 
[GCC 4.0.1 (Apple Computer, Inc. build 5341)] on darwin

% uname -a
Darwin chrysophylax 8.7.0 Darwin Kernel Version 8.7.0: Fri May 26 
15:20:53 PDT 2006; root:xnu-792.6.76.obj~1/RELEASE_PPC Power 
Macintosh powerpc

Output report:
===========================================
===========================
FAIL: test_find (ctypes.test.test_macholib.MachOTest)
------------------------------------------------------------
----------
Traceback (most recent call last):
  File "/usr/local/src/python2.5/Lib/ctypes/test/test_macholib.py", line 
55, in test_find
    self.failUnless(result.startswith('/usr/lib/libz.1'))
AssertionError

------------------------------------------------------------
----------
Ran 287 tests in 0.933s

FAILED (failures=1)
Traceback (most recent call last):
  File "Lib/test/test_ctypes.py", line 12, in <module>
    test_main()
  File "Lib/test/test_ctypes.py", line 9, in test_main
    run_suite(unittest.TestSuite(suites))
  File "/usr/local/src/python2.5/Lib/test/test_support.py", line 426, in 
run_suite
    raise TestFailed(err)
test.test_support.TestFailed: Traceback (most recent call last):
  File "/usr/local/src/python2.5/Lib/ctypes/test/test_macholib.py", line 
55, in test_find
    self.failUnless(result.startswith('/usr/lib/libz.1'))
AssertionError