MOD_PYTHON ERROR

ProcessId:      4612
Interpreter:    'lists.launchpad.net'

ServerName:     'lists.launchpad.net'
DocumentRoot:   '/srv/lists.launchpad.net/var/mailman/mhonarc'

URI:            '/maria-developers/msg08030.html'
Location:       None
Directory:      '/srv/lists.launchpad.net/var/mailman/mhonarc/maria-developers/'
Filename:       '/srv/lists.launchpad.net/var/mailman/mhonarc/maria-developers/msg08030.html'
PathInfo:       ''

Phase:          'PythonAccessHandler'
Handler:        'launchpad_lists_handler::protect'

Traceback (most recent call last):

  File "/usr/lib/python2.7/dist-packages/mod_python/importer.py", line 1537, in HandlerDispatch
    default=default_handler, arg=req, silent=hlist.silent)

  File "/usr/lib/python2.7/dist-packages/mod_python/importer.py", line 1229, in _process_target
    result = _execute_target(config, req, object, arg)

  File "/usr/lib/python2.7/dist-packages/mod_python/importer.py", line 1128, in _execute_target
    result = object(arg)

  File "/usr/lib/python2.7/dist-packages/launchpad_lists_handler/__init__.py", line 57, in protect
    lp_req.session.save()

  File "/usr/lib/python2.7/dist-packages/mod_python/Session.py", line 269, in save
    self.do_save(dict)

  File "/usr/lib/python2.7/dist-packages/mod_python/Session.py", line 404, in do_save
    _apache._global_lock(self._req.server, None, 0)

ValueError: Failed to acquire global mutex lock