Debian APT repos not found? Switch to the archive!

If you’re running an older release of Debian and you’re seeing messages like this when you try and apt-get installs, then it’s probably because your release has been taken off the main mirrors and can no longer be updated that way.

W: Failed to fetch http://ftp.uk.debian.org/debian/dists/lenny/main/binary-amd64/Packages  404 Not Found [IP: 83.142.228.128 80]
W: Failed to fetch http://ftp.uk.debian.org/debian/dists/lenny/main/source/Sources  404 Not Found [IP: 83.142.228.128 80]
W: Failed to fetch http://security.debian.org/dists/lenny/updates/main/binary-amd64/Packages  404 Not Found [IP: 195.20.242.89 80]
W: Failed to fetch http://security.debian.org/dists/lenny/updates/main/source/Sources  404 Not Found [IP: 195.20.242.89 80]
E: Some index files failed to download, they have been ignored, or old ones used instead.

You essentially have two choices; either upgrade your distribution to the latest release, or switch to the archive mirrors.

In general when I’m in a hurry I like to just switch to the archive mirrors because it’s quick and I usually don’t want to get into distribution upgrades in the middle of the day.

With that in mind, it’s pretty simple.

First, edit your /etc/apt/sources.list file. Comment out (or delete) everything except your primary mirror reference. It’ll look something like this:

deb http://ftp.uk.debian.org/debian/ lenny main
deb-src http://ftp.uk.debian.org/debian/ lenny main

To update this to the archive mirror, change these lines to:

deb http://archive.debian.org/debian/ lenny main
deb-src http://archive.debian.org/debian/ lenny main

Save the file and return to the console.

Next, you need to purge the APT cache, this is a simple:

apt-get clean all

Finally, you probably need to update the GPG keyring. If not, you’ll probably see errors that look like this:

W: GPG error: http://archive.debian.org lenny Release: The following signatures were invalid: KEYEXPIRED 1337087218
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AED4B06F473041FA

To update the keyring, simply run this command:

apt-get install debian-archive-keyring

…and you’re all done. You should be able to use apt-get install normally as before.