Comment 4 for bug 657812

I seem to have the same problem. I ran System/Administration/Update Manager and it offered an upgrade to '10.10'. I clicked the button to upgrade, and typed my password when asked. The "Distribution Upgrade" window got as far as "Setting new software channels" and said it would disable some non-standard ones (presumably the NetworkManager PPA documented at <https://wiki.ubuntu.com/DebuggingModemmanager>). Then I got a dialogue box saying:

"Invalid package information

"After your package information was updated the essential package 'ubuntu-minimal' can not be found anymore.
This indicates a serious error, please report this bug against the 'update-manager' package and include the files in /var/log/dist-upgrade/ in the bug report."

I've attached a tarball of my /var/log/dist-upgrade, since there's a directory structure there that makes attaching individual files awkward.