Ctrl-Alt-F1 I tried to login from text console, and it worked. From there, I was able to run a desktop session with
startx. So there was something wrong, but not terribly wrong, and it was happening after authentication and before desktop bring-up. Yesterday I did an
aptitude safe-upgrade, so maybe one of the packages that I upgraded had a regression bug. I noticed that, when login screen hanged, basically the only process of the user that tried to login (listed with “
ps -eu username“) was a
gnome-keyring-daemon process. I checked “
/var/log/apt/history.log“, and among the packages that I upgraded were
aptitude why gnome-keyring” and “
aptitude why libpam-gnome-keyring” I discovered that the only reason why I have these packages installed is that they are recommended from
gvfs-backends, which is a package useful to mount filesystems as a user. I think the configuration file that makes
gnome-keyring run at login is located in “
/etc/pam.d/gdm“, where the relative module is considered optional, so it will be loaded if it is installed on the system.
Eventually I ran “
aptitude remove gnome-keyring libpam-gnome-keyring” and at the next restart the computer didn’t hang anymore at login. I don’t know the real cause of this problem, but I hope this workaround will be useful to someone.