For a months now I've been getting a pesky error from Update Manager when checking for updates:
W:Failed to fetch http://archive.canonical.com/ubuntu/dists/intrepid/Release Unable to find expected entry main/binary-i386/Packages in Meta-index file (malformed Release file?)
This is probably something that most linux users see in some form at one time for another and while I had googled it a few times, I had not managed to resolve it. This was OK because while a bit annoying, it was not a show-stopper as I could simply dismiss the error and continue on my way.
That was, until today, when I finally got around to upgrading to Ubuntu Jaunty. The problem went from being a nuisance to a genuine problem as it caused the dist-upgrade to fail.
Determined to find a way around it, I again began by searching the Ubu-forums for simply the tail end of the error (beginning with "Unable to find..."). This time, I found a thread where someone actually had an issue similar to mine and had managed to find the issue. The problem in my case was two incomplete lines in my sources.list, namely:
deb http://archive.canonical.com/ubuntu intrepid main
deb-src http://archive.canonical.com/ubuntu intrepid main
As one person on the forums put it, "They should all end intrepid something". Sure enough, commenting out these two lines resolved the issue! How I ended up with two incomplete lines, I have no idea: as a rule I try to avoid editing sources.list by hand to avoid issues such as this one, save when adding third-party repos (which these two were not).
At any rate, the problem is solved at last and I am downloading the updates for Jaunty as I write this.