Login with compat SSO email requires email address

[matrixbot]

This issue was originally created by @dklimpel at matrix-org/matrix-authentication-service#3112.

What I did:

• create a new user with cli without mail address
• set email_change_allowed to false
• login with SSO with Synapse-Admin with the new user
  • login via /login, /complete-compat-sso
• MAS redirects to /add-email
  • returns error 500

Apparently there is an obligation to use a mail address.

Version: MAS 0.10.rc0

[matrixbot]

This comment was originally posted by @sandhose at matrix-org/matrix-authentication-service#3112 (comment).

MAS still requires for now that users have a valid primary email address to do any kind of client login (compat or OAuth 2.0).
The feature to make that optional is tracked in #1505
A way to work around this is to register the user using the CLI with a dumb email.

What's not normal is the 500 error you get on /add-email