fucked

$ sudo gem update
sudo: uid 501 does not exist in the passwd file!
$ whoami
501
$ grep 501 /etc/passwd
$ grep magnus /etc/passwd

## Oh shit. Let's open a new shell:
Password:
Login incorrect
login: root
Password:
Login incorrect
login: root
Password:
Login incorrect
login: root
Password:
Login incorrect
login: 

## Okay. Back to the current shell:
$ passwd
you don't have a login name
$ su -
su: who are you?

## I think I'm fucked.
## I can't open any .app. They don't even bounce in the dock.