Fix "Ignoring File .save In Directory /etc/apt/sources.list.d/ As It Has An Invalid Filename Extension" In Ubuntu 10.10

I just did a clean Ubuntu 10.10 Maverick Meerkat install on my main computer. Not because I wanted but because my Lucid install was very unstable do to the lost of tests I do for WebUpd8 posts (don't worry, if something I test goes bad, I don't post it on WebUpd8 so everything we post is mostly stable). I tried to upgrade from Ubuntu 10.04 to Ubuntu 10.10 but it didn't go too well. Actually it didn't boot at all with some serious crashes while booting so I did a fresh install.

I didn't encounter any major bugs in Ubuntu 10.10 so far, but there's one small but very annoying bug: after you add a PPA and run "sudo apt-get update", an error is displayed:

N: Ignoring file 'THE_PPA.list.save' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension

And the more PPAs you add, the more errors like this you'll be getting. And you can't install anything from those PPA until you remove all the .save files from /etc/apt/sources.list.d/ manually.

But I found a permanent fix in a comment on this bug so you don't have to keep deleting files from /etc/apt/sources.list.d/. Simply run the following command in a terminal:

echo "Dir::Ignore-Files-Silently:: \"(.save|.distUpgrade)$\";" | sudo tee /etc/apt/apt.conf.d/99ignoresave