I am having some issues with the OOTB
SiteRegistrationController and corresponding page. It works fine unless I try to register a new user with the same Username. In this case it errors with
Your request cannot be processed at this time. This site administrator has been alerted.
It does not email the admin on the company profile page(me). I have been unable to get the debug logs to trace this class. So I have been running it anonymously to try and figure out what is going on and why it does not handle this situation. This seems like it should be OOTB functionality, which makes me feel like I am missing something.
I have found this issue on ideas. Yet it has more comments than it does votes(1).