Bug#681282: gdm3: gdm does not start the login window

[Antoine Sirinelli]

> When this happens, can you grab the contents
> of /var/log/gdm/:0-greeter.log ?

Since the upgrade, :0-greeter.log files are no longer generated. There is
only :0.log (which looks normal) and :0-slave.log produced.

Here is what you have in :0-slave.log (1 line):

gdm-welcome][2869]: pam_unix(gdm-welcome:session): session opened for user Debian-gdm by (uid=0)

Antoine