AttributeError: 'bool' object has no attribute 'lower'

[dennis.liou@…]

Can any one help me debug the error?

Traceback (most recent call last):
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 512, in _dispatch_request
    dispatcher.dispatch(req)
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 221, in dispatch
    resp = chosen_handler.process_request(req)
  File "build/bdist.linux-x86_64/egg/trac/wiki/web_ui.py", line 134, in process_request
    req.perm(versioned_page.resource).require('WIKI_VIEW')
  File "build/bdist.linux-x86_64/egg/trac/perm.py", line 577, in require
    if not self._has_permission(action, resource):
  File "build/bdist.linux-x86_64/egg/trac/perm.py", line 568, in _has_permission
    check_permission(action, perm.username, resource, perm)
  File "build/bdist.linux-x86_64/egg/trac/perm.py", line 460, in check_permission
    perm)
  File "build/bdist.linux-x86_64/egg/trac/perm.py", line 294, in check_permission
    get_user_permissions(username)
  File "build/bdist.linux-x86_64/egg/trac/perm.py", line 396, in get_user_permissions
    for perm in self.store.get_user_permissions(username) or []:
  File "build/bdist.linux-x86_64/egg/ldapplugin/api.py", line 209, in get_user_permissions
    users += list(provider.get_permission_groups(username))
  File "build/bdist.linux-x86_64/egg/ldapplugin/api.py", line 108, in get_permission_groups
    self._ldap = LdapConnection(self.env.log, bind, **self._ldapcfg)
  File "build/bdist.linux-x86_64/egg/ldapplugin/api.py", line 540, in __init__
    self.__setattr__(k, v.lower() in _TRUE_VALUES)
AttributeError: 'bool' object has no attribute 'lower'}}}