Sure, I can add more logging here.

actually, there are two cases I conflated.  The `DoesNotExist` case is pretty common (every normal login for a user without external auth), so I'm not sure if you want to log that.  I still can, but not sure you if guys want to add this stream of activity.  In any case its level would be log.info(), I think.

The `MultipleObjectsReturned` is certainly an error, and I should log.exception and re-raise.