I have a second username tied to my account, sharing the same user id, so that
I can log in with a second password (which does not unlock some encrypted stuff
This has worked fine until accountsservice-0.37. After that it broke and GDM
would not show up anymore.
AFAIK multiple username/password for the same user id are legal and they should
not confuse accountsservice.
*** Bug 93775 has been marked as a duplicate of this bug. ***
I don't have a reference handy, but this got fixed at some point.