I have yet to be able to test it, but from mozilla/playdoh#117 it seems that the auth backend for django-browserid causes a DeprecationWarning to be raised in django 1.4.
/home/vagrant/project/vendor/lib/python/django/contrib/auth/init.py:26: DeprecationWarning: Authentication backends without a supports_inactive_user attribute are deprecated. Please define it in .
[21/Jun/2012 08:03:21] "POST /en-US/browserid/browserid/verify/ HTTP/1.1" 302 0
[21/Jun/2012 08:03:21] "GET / HTTP/1.1" 301 0
Fix #67: Add supports_inactive_user to auth.