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

Logged In: YES 
user_id=45365

Ronald: just guesing that you know more about this than I do...

Logged In: YES 
user_id=580910

This is a rather annoying, but shallow, failure. Dlopen on osx is quite touchy 
about the flags you use to open a shared library.

Anyway, all tests pass on the trunk and 2.5 branch, I guess this was fixed before 
2.5 was released. I have had an e-mail exchange with Thomas Heller about a 
simular issue and he has checked in a fixed for that before 2.5 was released.\

I'm therefore closing this issue.

Logged In: YES 
user_id=995094

As of 2006-10-9 I still get this error compiling on 
OS X 10.4.8
Python 2.5 (r25:51908, Oct  9 2006, 11:15:40) 

test_ctypes
test test_ctypes failed -- Traceback (most recent call last):
  File
"/Users/robrien/src/Python-2.5/Lib/ctypes/test/test_macholib.py",
line 55, in test_find
    self.failUnless(result.startswith('/usr/lib/libz.1'))
AssertionError

Logged In: YES 
user_id=995094

As of 2006-10-9 I still get this error compiling on 
OS X 10.4.8
Python 2.5 (r25:51908, Oct  9 2006, 11:15:40) 

test_ctypes
test test_ctypes failed -- Traceback (most recent call last):
  File
"/Users/robrien/src/Python-2.5/Lib/ctypes/test/test_macholib.py",
line 55, in test_find
    self.failUnless(result.startswith('/usr/lib/libz.1'))
AssertionError

reedobrien: can you still reproduce the problem?

I'll close this issue unless we can confirm it's still present.

I am no longer using OSX 10.4.x, but this issue appears fixed in 2.5.4
and 2.6.1 on OSX 10.5.6

I have no reason for this to stay open

Setting issue back to "open". I'm going to install a 10.4 PPC test machine 
over the weekend to try to reproduce the problem there.  

Issue5413 might be related to this one, that one also seems to be about 
some ctypes code that doesn't work on a PPC system (10.5 server in that 
case).

Can this now be closed?

Verified that the ctypes test_macholib tests in current Python 2.7, 2.6.6, and even 2.5.3 run without failure on OS X 10.4.11 PPC.

FYI: The analysis in Issue21093 suggests a probable failure cause: a local copy of libz in either $HOME/lib or /usr/local/lib.