Tried to upgrade from 10.04 -> 11.04, how to fix broken packages?

Question

I tried to upgrade 10.04 -> 11.04. Long story short, i had to terminate the upgrade process, and now i can't start it again. It says different stuff about broken packages, dependencies, and i have no idea how to fix this. Here's what i've tried:

You have 2 broken packages on your system!

Use the "Broken" filter to locate them.

Ok, i located them, tried to mark for reinstall, removal, etc, but i cannot apply changes:

Could not apply changes!
Fix broken packages first.

What should i do now?

Also i tried:

ilya@ilya-X38-DQ6:~$ sudo apt-get upgrade -f
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... failed.
The following packages have unmet dependencies:
 libc6 : Depends: libc-bin (= 2.12.1-0ubuntu10.2) but 2.13-0ubuntu13 is installed
 libnih1 : Depends: libc6 (> 2.13~) but 2.12.1-0ubuntu10.2 is installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
E: Unable to correct dependencies

Answer 1

You said that you tried to upgrade from 10.04 straight to 11.04. Please can you confirm that you upgraded to 10.10 first before upgrading to 11.04? If you didn't, then this is you key problem. The correct upgrade path is 10.04 --> 10.10 --> 11.04.

If you havent upgraded through the correct upgrade path, then restore from a backup image. If you havent got a backup then boot from a live CD and copy to a USB stick the most valuable data from your hard-drive. Then reinstall a fresh 11.04 image.