Ubuntu 10.04: Problems with Update Manager and Software Sources

As described elsewhere, I was in the process of upgrading from Ubuntu 9.10 to 10.04 (Lucid Lynx).  I went into System > Administration > Update Manager.  At first, the system reported that I was up to date, as it often would do even when the system was terribly out of date.  I clicked Check and wound up with a message indicating that there was a problem with a repository.  I looked into System > Administration > Software Sources > Other Software.  The error message didn't make sense in light of what I saw there.  I tried Update Manager again.  This time it worked:  it was ready to install a bunch of updates for 9.10.  I skipped that and instead told it to upgrade the system to 10.04.  It did.

I ran Update Manager again, just to be sure.  Now I got the repository error message mentioned above.  It said this:

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/lucid/Release.gpg.  Could not resolve 'us.archive.ubuntu.com'

There were a bunch of other, similar messages after that one, referring to other "Failed to fetch" problems.  I closed Update Manager and went into Software Sources, to see what this was about.  The sources listed there did not make sense, given that System > About Ubuntu reported that I was indeed running 10.04.  I checked them all -- the 9.10 CDROM, two "Unsupported updates" entries, and the http://archive.canonical.com/update karmic entries.  I went through the other tabs in Software Sources, while I was there, and made a few other changes, and then closed out.  It checked for updates and again gave me an error:

Could not download all repository indexes
The repository may no longer be available or could not be contacted because of network problems . . . .

followed by similar "Failed to fetch" messages, e.g., "Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/lucid/main/i18n/Translate-en_US.bz2 Connection failed."  Before attacking that, I decided to take care of the next of my previous posts on the whole upgrade and tweaking process.  This post had to do with installing a PAE kernel to take advantage of all of my RAM.  This was just a matter of searching for PAE in Synaptic and selecting and installing linux-generic-pae and linux-headers-generic-pae.  But that process failed with, again, some "Failed to fetch" messages.  This time, though, the messages said something about "Got a single header line over 360 chars" and "Bad header line."

So, OK, I was going to have to fix this repository problem before going any further.  I ran a search and came up with Salamane Moustapha's To-Do List After Installing Ubuntu 9.10.  The first thing on his list was to expand the software repository list.  That was actually the very next thing in my own sequence of previous posts, so I went to that one.  It called for installing Ubuntu Tweak, which I had already downloaded, and then running it from Applications > System Tools.  I went down the list in Ubuntu Tweak, making various adjustments.  When I got to the Source Center option, there were no sources listed.  This was no surprise; I had removed all those old ones from Software Sources, and now there was nothing left.  I moved on to the next Ubuntu Tweak item, Source Editor, and here I saw a number of repositories listed.  These seemed to be the ones actually active on my system at this point, as represented by the Ubuntu Software tab in Software Sources.  So far, in other words, Ubuntu Tweak was not solving all of my problems.  The only other things I changed in Ubuntu Tweak at this point were under Default Folder Locations, Manage Scripts, and Nautilus Settings.

Moustapha's To-Do List gave me a large set of repositories.  I was going to follow his instructions and just replace my sources.list with his.  His list was for Ubuntu 9.10, so I figured I would wind up deleting or modifying some from his list.  Then I rediscovered the Ubuntu Sources List Generator, and used that instead.  I didn't select any source code items, and in the Third Parties list I only chose GetDeb, Google Linux Software Repositories, MediaInfo, Medibuntu, Themes, Wine, and X Updates.  There were lots of other interesting programs there, but I thought it might be simpler to just install them via Synaptic as I needed them.  I clicked "Generate List."  Then, in Terminal, I typed "sudo gedit /etc/apt/sources.list."  I deleted its contents and copied their generated list over into it.  I saved and closed that and then copied and pasted, into Terminal, their supplied list of commands to get keys.  The first one, for GetDeb, produced an error:  "gpg: no valid OpenPGP data found."  The solution there was to execute the command with "sudo" in front; so I typed "sudo -i" to eliminate further recurrences of that problem in this session.  The next command provided by the Ubuntu Sources List Generator was "sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F9D8BC54."  This one produced these errors:

gpgkeys: HTTP fetch error 7:  couldn't connect to host
gpg: no valid OpenPGP data found.

A search for that specific key number (F9D8BC54) turned up nothing.  I skipped that command for the moment and went on to the next.  This one was for Medibuntu.  It gave me five error messages.  One was for medibuntu itself, and it went like this:

W: GPG error: http://packages.medibuntu.org/ lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783

The other four were of the same form, but they referred to http://ppa.launchpad.net/ and their public keys were 61260473F9D8BC54 (see above), 6E871C4A881574DE, 5A9A06AEF9CB8DB0, and 3B22AB97AF1CDFA9.  These four (but not the Medibuntu one) repeated again at the end of the installation.  Despite these errors, I ran the next command.  This one referred to key 881574DE, which seeems to have been one of the several just listed.  It seemed that maybe the Ubuntu Sources List Generator had gotten things out of order -- that perhaps I should have run this key request first.  But no, it gave me the same error messages as above, regarding HTTP fetch error 7 and no valid OpenPGP data.  Same thing for the final two commands supplied by the Ubuntu Sources List Generator, regarding keys F9CB8DB0 and AF1CDFA9.  Searches for these led to the suggestion to use this command (inserting, here, the full numbers from above):

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 2EBC26B60C5A2783 61260473F9D8BC54 6E871C4A881574DE 5A9A06AEF9CB8DB0 3B22AB97AF1CDFA9

But this still gave me the "HTTP fetch error 7."  A post from Oscar said that, in his case, the desired repository had been installed nonetheless.  In Software Sources > Authentication tab, I saw that I had keys for GetDeb, Google, and Medibuntu, from those that I had requested, along with Ubuntu Archive, Ubuntu CD Image, and Launchpad PPA, which came first in the list and which, I guessed, had been there before I made this request.  So the Authentication tab was not telling me that the others had been installed.  But Software Sources > Other Software did list them all, so in that sense I did seem to have added them successfully.  I posted a question on this and let the matter sit.  I went back to Update Manager, and this time it ran OK.  I ran it again, but unfortunately this time I got "the public key is not available" error messages for those same items again.  So I had not solved that problem.  I did not proceed further with this effort.  Instead, this and other problems prompted me to reinstall Ubuntu 10.04 from scratch.