Right now attempting to log in with Persona when an account does not exist results in an error.
Unfortunately, account auto-creation cannot be supported because MediaWiki registration requires a username, which Persona cannot provide.
However, at the very least, we can redirect the user to the account creation form with the email address pre-filled or something like that. That way the user doesn't have to jump around and gets a more uniform experience.
Version: master
Severity: enhancement