Traceback thrown at my face when trying to connect to Trac

When I tried to connect to trac, the following message was thrown at my face (not the first time):

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 710, in send_error
    data, 'text/html')
  File "/usr/lib/python2.7/dist-packages/trac/web/chrome.py", line 1108, in render_template
    message = Markup(req.session.pop('chrome.%s.%d'
  File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 492, in __getattr__
    value = self.callbacks[name](self)
  File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 350, in _get_session
    return Session(self.env, req)
  File "/usr/lib/python2.7/dist-packages/trac/web/session.py", line 242, in __init__
    if req.authname == 'anonymous':
  File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 492, in __getattr__
    value = self.callbacks[name](self)
  File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 172, in authenticate
    authname = authenticator.authenticate(req)
  File "build/bdist.linux-x86_64/egg/acct_mgr/util.py", line 81, in wrap
    return func(self, *args, **kwds)
  File "build/bdist.linux-x86_64/egg/acct_mgr/web_ui.py", line 451, in authenticate
    username = self._remote_user(req)
  File "build/bdist.linux-x86_64/egg/acct_mgr/web_ui.py", line 766, in _remote_user
    if acctmgr.check_password(username, password) is True:
  File "build/bdist.linux-x86_64/egg/acct_mgr/api.py", line 287, in check_password
    valid = store.check_password(user, password)
  File "build/bdist.linux-x86_64/egg/acct_mgr/htfile.py", line 69, in check_password
    return self._check_userline(user, password, line)
  File "build/bdist.linux-x86_64/egg/acct_mgr/htfile.py", line 207, in _check_userline
    return suffix == htpasswd(password, suffix)
  File "build/bdist.linux-x86_64/egg/acct_mgr/pwhash.py", line 140, in htpasswd
    available."""))
NotImplementedError: Neither are "sha2" hash algorithms supported by the
                    "crypt" module on this platform nor is "passlib"
                    available.