Mod_python error: "PythonHandler trac.web.modpython_frontend"

Traceback (most recent call last):

  File "/usr/local/lib/python2.4/site-packages/mod_python/apache.py", line 299, in HandlerDispatch
    result = object(req)

  File "/usr/local/lib/python2.4/site-packages/trac/web/modpython_frontend.py", line 87, in handler
    gateway.run(dispatch_request)

  File "/usr/local/lib/python2.4/site-packages/trac/web/wsgi.py", line 87, in run
    response = application(self.environ, self._start_response)

  File "/usr/local/lib/python2.4/site-packages/trac/web/main.py", line 377, in dispatch_request
    env = _open_environment(env_path, run_once=run_once)

  File "/usr/local/lib/python2.4/site-packages/trac/web/main.py", line 58, in _open_environment
    env_cache[env_path] = open_environment(env_path)

  File "/usr/local/lib/python2.4/site-packages/trac/env.py", line 434, in open_environment
    env = Environment(env_path)

  File "/usr/local/lib/python2.4/site-packages/trac/env.py", line 121, in __init__
    load_components(self)

  File "/usr/local/lib/python2.4/site-packages/trac/loader.py", line 140, in load_components
    __import__(module)

  File "/usr/local/lib/python2.4/site-packages/trac/versioncontrol/svn_fs.py", line 56, in ?
    from svn import fs, repos, core, delta

  File "/usr/local/lib/python2.4/site-packages/svn/fs.py", line 19, in ?
    from libsvn.fs import *

  File "/usr/local/lib/python2.4/site-packages/libsvn/fs.py", line 29, in ?
    import core

  File "/usr/local/lib/python2.4/site-packages/libsvn/core.py", line 3342, in ?
    svn_pool_create()

  File "/usr/local/lib/python2.4/site-packages/libsvn/core.py", line 1137, in svn_pool_create
    return apply(_core.svn_pool_create, args)

TypeError: argument number 0: a 'apr_pool_t *' is expected, 'instance()' is received