I thought I'd give this unsupported upgrade a go to see if it would actually work. Wow, just as I thought, it totally nose dived! I love you Debian, for all your flaws. Anyway, all was not lost. The failure occurred as a result of glibc6 being uninstalled without being replaced by the upgraded glibc6. Something went horribly wrong after uninstall, when something couldn't be restarted as a result of not having glibc6 available; yet another argument that suggests package managers should queue post install scripts until the end of installing all packages rather than trying to do a half arsed install and messing it up.
Anyway, since aptititude kindly caches all the downloaded packages in /var/cache/apt/archive, it was easy to reinstate a working glibc6, providing I didn't reboot!
$ dpkg -i $(ls -t1 /var/cache/apt/archive/*glibc6*.deb | head -1)
After that, just running the dist-upgrade again managed to get the upgrade merrily on its way. So my tip of the day:
No matter how bad you think the situation is, you can make it worse by hitting the reset button!
