If you type the wrong PPA address when adding a PPA or you add a PPA that doesn't provide packages for your Ubuntu version, you'll get a "404 Not Found" error message when running "apt-get update".
These errors are pretty much harmless (though they probably slow down "apt-get update" a bit) but if you want to get rid of them anyway, you must disable the PPAs that cause the 404 errors via Software Sources. If you want an easier, automated way to disable the PPAs that cause these errors, give "fix404" a try.
"fix404" is a simple script that checks for "404 not found" messages for all the PPAs added to your software sources and prompts you to disable them:
"fix404" will prompt twice for each PPA - that's because it needs to disable both the binary and the source line.
By the way, if you want to check which Ubuntu versions are supported by each PPA you've added, use "checklp".
The "fix404" PPA is only available for Ubuntu 11.04 Natty Narwhal - add it and install it using the commands below:
sudo apt-add-repository ppa:lkjoel/fix404 sudo apt-get update sudo apt-get install fix404
For other Ubuntu versions, you can download the .deb file from HERE.
To use "fix404", run the following command in a terminal:
Also see: Launchpad-Getkeys, a tool to automatically import all missing PPA GPG keys.
Thanks to lkubuntu for the script!