ImportError when running WSGI app in Apache: undefined symbol: PyUnicodeUCS2_DecodeUTF8

Question

I'm trying to run MoinMoin under Apache on SLES 11P1. I'm getting the following error in my Apache log when somebody tries to access the site:

mod_wsgi (pid=20772): Target WSGI script '/srv/www/wiki/moin.wsgi' cannot be loaded as Python module.
mod_wsgi (pid=20772): Exception occurred processing WSGI script '/srv/www/wiki/moin.
wsgi'.
Traceback (most recent call last):
  File "/srv/www/wiki/moin.wsgi", line 44, in <module>
    from MoinMoin.web.serving import make_application
  File "/usr/local/lib64/python2.6/site-packages/MoinMoin/web/serving.py", line 14, in <module>
    from MoinMoin import version, log
  File "/usr/local/lib64/python2.6/site-packages/MoinMoin/log.py", line 92, in <module>
    import logging.config
  File "/usr/lib/python2.6/logging/config.py", line 30, in <module>
    import sys, logging, logging.handlers, string, socket, struct, os, traceback, types
  File "/usr/lib/python2.6/logging/handlers.py", line 27, in <module>
    import logging, socket, types, os, string, cPickle, struct, time, re
ImportError: /usr/lib64/python2.6/lib-dynload/cPickle.so: undefined symbol: PyUnicodeUCS2_DecodeUTF8

However, I have no problem if I execute the failing statement manually from a Python interpreter:

$ python
'import site' failed; use -v for traceback
Python 2.6.6 (r266:84292, Feb 17 2011, 08:36:48) 
[GCC 4.3.4 [gcc-4_3-branch revision 152973]] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import logging, socket, types, os, string, cPickle, struct, time, re
>>>

What could cause that error when running under Apache, but not when running Python at the command-line?

Edit: It looks like they are hitting different shared libraries. Apache is hitting /usr/lib64/python2.6/lib-dynload/cPickle.so and the Python interpreter that I invoke at the command-line is hitting /usr/lib/python2.6/lib-dynload/cPickle.so

$ python -v 
...
>>> import cPickle
dlopen("/usr/lib/python2.6/lib-dynload/cPickle.so", 2);
dlopen("/usr/lib/python2.6/lib-dynload/cStringIO.so", 2);

Answer 1

As yourself have noted that Apache (64-bit) is loading different libraries while you are executing different python binary from command line. Fix the binaries/libraries for 64-bit installation of Python2.6. This should hopefully go away.