upgrate to 10.10 causes error ubuntu-minimal missing

Thanks for your report.

Are you directly connected to the Internet or behind a firewall, proxy, ... or using an apt cache, or having a 10.10 CDROM loaded into your drive or anything else unusual that you could think ?

It looks like the files served where empty:

2010-10-10 16:02:39,140 DEBUG /openCache(), new cache size 1765

could you please attach the output of
$ ls -la /var/lib/apt/lists ?

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.

To answer the later questions, I'm behind a fairly dull NAT router, on a network that (on a good day) supports IPv6, and I've attached the output of "ls -la /var/lib/apt/lists".

So, I seem to have found a workaround for my case:

1: Configure my IPv6 router to only advertise the correct prefix rather than a correct one and a bogus one.
2: Reconfigure the IPv6 method on my "Auto eth0" network connection in NetworkManager to "Automatic, addresses only" instead of "Ignore".

I think the first of those was the critical one; the second just forced my Ubuntu box to pick up the change.

Having done those, the upgrade gets as far as asking me to shut down all applications, which it didn't before.

It seems to me that there's still a bug here -- a broken network should not cause update-manager to ask me to file a bug report.

This seems to be a duplicate of bug #631426