A urlconf that does not define those as keyword arguments.

    url(r'^reset/$', 'password_reset_confirm', name='password_reset_confirm'),

Also, I'm emulating what django does with a 404 rather than an assertion.  Maybe this should be an assertion instead to raise a louder error.

https://github.com/django/django/blob/master/django/contrib/auth/views.py#L198