problems with 10.04 upgrade to 12.04

[Dave Howorth]

I have a 10.04 machine that I just tried to upgrade to 12.04. I used
update-manager-text. It ran and at the end said something like 'upgrade
completed but there were errors'. Unhelpfully, it didn't give me the
option to see the errors or tell me where it keeps a log etc.

I tried to discover using google and found
https://wiki.ubuntu.com/DebuggingUpdateManager but sadly that gave a 500
internal error. The page now seems to have fixed itself but it's not
relevant to my problem.

I rebooted and the system came up but via a partly broken boot process.
I appear now to be back in 10.04 and the system warns me there are 52
broken packages. But the simple commands I've done so far have been OK.

How do I:
- find out what went wrong
- set about fixing broken things
- set about completing the upgrade

Any pointers gratefully received.
Cheers, Dave