Upgrading to Kubuntu 13.04 from 12.10 breaks Ubuntu 13.04 in VirtualBox

Another post in my short saga of upgrading to Kubuntu 13.04.

The situation

So here's my scenario: I'm running Kubuntu 12.10 and all is well (enough). In a VirtualBox instance I have a copy of Ubuntu 13.04 that I'm keeping up to date as it gets closer to release. In all, everything in working fine as I work inside the VM and prod at it from the outside.

Suddenly my system starts to act a bit flaky, and ultimately freezes up completely. I suspect this is actually an audio driver issue, and I figure Kubuntu 13.04's new kernel may just fix it, so I decide to upgrade to Kubuntu 13.04 after doing a hard-reset to recover from the lockup.

Debugging a hosed virtual machine

The upgrade goes smoothly enough, but my virtual machine is now completely baffooned. The screen comes up but is just the default purple wallpaper. Clicking does nothing. Eventually I get an error message that there was a system failure and perhaps rebooting will make things better. There is a button on the dialog that says "Continue" (or "OK") but doesn't show up until you hover over it. Rebooting does not help.

From the VirtualBox 'Machine' menu I can send the Ctrl-Alt-Delete signal and this is captured correctly. I can log out and log back in, but this changes nothing. I can get to a command prompt by hitting <Host>-<F1> and log in there. I create a new user with 'adduser', hit <Alt>-<F7> to return to the GUI, and log in as the new user ... but the new user has the same problem. This means that the default user account is likely fine and the problem is elsewhere.

I go to the Devices menu in VirtualBox and mount the new Guest Additions. I go back to the command prompt and install these as root. While this step is probably necessary (this is a new version of VirtualBox, afterall), it is insufficient to fix the problem. As the root user, I can run 'startx -- :1' but this presents the same type of problems.

So I reset the machine and think a bit. The VM is setup to auto-login the default user, so I leave X running and go back to the command prompt via <Host>-<F1>. I log in and try running things from the command line:

DISPLAY=unix:0 compiz

Interesting - compiz is crashing with I/O errors and complaining about not being able to access sessions, waiting for dbus to respond, not able to access pixmaps, etc. In short, complete madness. But I can run

DISPLAY=unix:0 gnome-terminal

and, after installing metacity,

DISPLAY=unix:0 metacity --replace

Some searching suggests these compiz errors have been around for a long time and therefore aren't likely to help. However, one post recommends reinstalling ubuntu-desktop. This package is already up to date, but they go on to suggest installing it from the Ubuntu Software Center. This doesn't make much sense but what could it hurt? Suddenly, I find myself strace'ing software-center trying to figure out why it's crashing and, furthermore, why it's complaining about not being able to find icons.

The ugly fix

I try reinstalling the icons it appears to be complaining about but that doesn't work. Eventually, I give up, and decide to just reinstall the entire system. For me, this doesn't mean getting out a CD, however. It means -- (a) print a list of every available package - (b) print the names of the packages that are installed - (c) filter out the packages that contain circular dependencies - and (d) reinstall them live.

apt-get install --reinstall `dpkg -l '*' | awk '/^ii/ { print $2 }' | egrep -v '(mountall|perl-base|libpam-modules|kbd|ntpdate|resolvconf|ifupdown|dpkg|bash|debconf)'`

Somewhere in there, despite some unnecessary exclusions, magic. The best part is that all my settings are retained so I don't need to reconfigure any of my settings.