An Exception Has Occurred

Python Traceback

Traceback (most recent call last):
  File "/srv/web/viewvc/lib/viewvc.py", line 3766, in main
    request.run_viewvc()
  File "/srv/web/viewvc/lib/viewvc.py", line 394, in run_viewvc
    self.view_func(self)
  File "/srv/web/viewvc/lib/viewvc.py", line 3014, in view_revision
    rev = request.repos._getrev(query_dict.get('revision'))
AttributeError: 'NoneType' object has no attribute '_getrev'