Comment 5 for bug 295859

I've had this problem happen just today on two machines.

Started an upgrade, walked away. 2 hours later came back, machines were sitting at login screen. Keyboard didn't work. Upon rebooting machine got kernel error unable to sync VFS. Fixed by reverting to old kernel, rerunning dpkg --configure -a, and rebooting. dpkg --configure -a broke the first time, with !quote.length or something. This was because a lot of packages were failing to configure, because dbus could not be configured. /var/run/dbus was missing. I mkdir'd /var/run/dbus and dpkg --configure then worked. Rebooted, machine works.

During dpkg --configure -a, the X server started, repeatedly. This was ODD. I've never seen a package configure screw up X so badly.

I can't really explain what went wrong. What I *think* happened is the upgrade crashed X. Whatever script was causing the flickering the second time around crashed X the first time around... leaving the upgrade busted. grub got updated, so the kernel was in the menu, but the initramfs had not been built. The script that was breaking X... I could not identify it.

The /var/run/dbus thing might be an independent problem. It might be that the preinst script creates it, and after rebooting it was removed, and configure does not create it. I'm not sure if this is a bug or not though. I'll file it anyways and see the responses.