Since Ubuntu Hardy had just come out, I figured it was a good time to upgrade my laptop and mythtv server to the new version (the rest of my machines still run straight debian, and I just apt-get install stuff on them from testing without ever doing apt-get dist-upgrade).
Since I'm not totally stupid, I upgraded my laptop first and things pretty much went OK (X broke, but that's because of my unsupported ATI firegl 5200 chip, that required the fglrx binary only driver at the time.

So, I decided to upgrade my mythtv next. I figured I might have to fix up a few things after the mythtv 0.20 to 0.21 upgrade, but things couldn't be so bad, could they?
Well, what actually happened is that my server never rebooted after I upgraded the kernel. Ok, no biggie, I wait to get home and see what's up, and what was up was that /dev/sda1 would mount, but none of my other partitions (/usr, /var, and others) would mount: e2fsck said the partition was busy, and /bin/mount refused to mount the partition because it was busy too.
WTF? They were not used in /proc/mounts, or anywhere. I was quite stumped, and debugging without /usr or /var wasn't fun (BTW, thanks debian/ubuntu switching from one crappy editor in /bin: ae, to another crappy editor: nano. What a lot of crap, just compile a small minimalistic vim or other vi clone and put it in /bin already!
Anyway, after much searching, I found out that the problem was due to evms. The upgrade helpfully removed my lvm2 scripts and stuck evms in there. Not only that, but they forced me to switch to evms!
But it gets better, the evms init script makes the partitions busy and prevents mounting them from their normal location (/dev/sdax) and forces the use of /dev/evms/sdax , unless you a using a non standard kernel patch that isn't in my kernel.org kernel.
And I love how the fix that is typically given is "apt-get remove evms" when that, in turn, removes lvm support and screws me over too...
To the geniuses who thought it was ok to pull that kind of crap: you suck. I don't care if it was somewhere in the release notes, you can't just force me to switch to evms, break/remove my lvm scripts, and depend on a non standard kernel for me to be able to see and mount my regular partitions and my lvm partition.
You cost me several days of myth downtime, lost shows, and therefore have blood on your hands!
And I don't care if evms is great, it's not the agreed upon future of linux, so forcing people to switch in a non revertable, non compatible change is just wrong on too many levels!

Ok, now I can focus on fixing what broke/changed in mythtv 0.21...