Getting around apt-get's too strict timestamp checks

Datum: 29.10.2009 14:40

Sometimes apt-get update produces errors like ...

W: Failed to fetch
http://at.archive.ubuntu.com/ubuntu/dists/jaunty-updates/universe/main/binary-amd64/Packages.bz2
Hash Sum mismatch

... and refuses to accept that archive.

Unfortunately neither apt-get clean (does not clean cached lists) nor cleaning any proxy help around.
Sometimes, aptitude update works, because aptitude makes less checks on timestamps of locally stored lists (against whatever the mirror's server timestamps the file) and/or uses other HTTP headers!?

This is all a flaw of the Debian archive and mirroring system ;-((

But finally, I seem to have found a solution:

rm /var/lib/apt/lists/*

... totally cleans locally cached package and forces apt-get to totally re-GET those files.
If you want to keep traffic minimal you might try to only delete the "bad" files.

Of course that won't help if the used mirror still is dirty from an ongoing update.

Background Update and workaround:

The problem is documented as Debian Bug 499379 (including a possible workaround) and Squid Bug 2624 (fixed 2009-09-24) and should be fixed in Debian/Ubuntu with their next upstream update of squid. Unfortunately even lucid's last upstream update of squid happened too early, of course - by 4 days.