Another Ubuntu upgrade, another critical upgrade bug. I had this idea that letting a solid chunk of time go by before upgrading (in this case, ~4 months) would mean most of the upgrade bugs would be gone. Instead, I was bit in the ass because using the current 7.10 Gutsy kernel (2.6.22-15) means the upgrade process will freeze on the locales package.
The workaround, found by siberoptik on the Ubuntu forums, is to reboot your system with the 2.6.22-14 kernel. Everything is peachy after that. Since I’m working remotely, the way I changed kernels was to edit /boot/grub/menu.lst and nuke the lines about the 2.6.22-15 kernel. That made 2.6.22-14 the top-most kernel. By the end of the upgrade none of those kernels will matter anymore anyway. If you are in front of the box, you can just press <Esc> at the grub menu.
If you find yourself in the middle of an upgrade, frozen at “Generating locales…”, all is not lost. Get another shell on the system, look for the process tree (`ps axfw`) with locale-gen running, and kill locale-gen off. For me, the upgrade continued on until the only packages left were ubuntu-minimal and locales. I had to kill off the locale-gen process a couple of more times until the upgrade process was declared “failed”.
At this point I reboot the box and something went awry as it didn’t come back again. 
It’s unclear from the logs what exactly happened (working remotely, I couldn’t watch the screen), but after a hard reset I was able to get back in again. Running `dpkg --configure -a` had the locales generate instantly and everything was fine.
The total joke about all of this is, as usual, it’s not documented on Ubuntu’s site in any useful place. Yes, I found it in the forum after I hit the bug and knew what to search for, but it’s a bit late at that point. You’d think there would be a “caveats” or “known problems” or “big nasty critical bugs you should avoid” section on the help page about Hardy upgrades.
In an effort to prevent others from going down this road, I’ve put information in the following places:
Update (2008.08.19): The bug I filed against update-manager as been made a duplicate of a bug in linux-source-2.6.22. A lot of talk has been happening there and someone claims the developers are working on a fix.
Update (2008.09.24): On August 25, a new kernel was released which fixed this problem. All the upgrades I’ve done with the new kernel have gone perfectly. That said, it does appear there are some people who are still running into this problem. See barbex’s comment below and see the bug in linux-source-2.6.22 page.
