I’m running Debian Etch because I prefer the stable Debian package tree. This is all great but the software is a little outdated compared to other distributions like Ubuntu. That is where backports come in. Backports are recompiled packages from testing (mostly) and unstable (in a few cases only, e.g. security updates), so they will run without new libraries (wherever it is possible) on a stable Debian distribution. They recommend you to pick out single backports which fits your needs, and not to use all backports available here.
Using backports is simple
deb http://www.backports.org/debian etch-backports main contrib non-free
You might get a error message
Reading package lists... Done W: GPG error: http://www.backports.org etch-backports Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EA8E8B2116BA136C W: You may want to run apt-get update to correct these problems
This message comes on Debian Etch because you haven’t imported the backports keyring. It’s easily fixed by running the command
apt-get install debian-backports-keyring
apt-get -t etch-backports install nmap
It is important to remember that if you forget to tell apt-get that nmap is installed from backports and run another apt-get install nmap it will remove my backports package.
A simple solution to this is to use pinning
Edit /etc/apt/preferences, the file has to be created if you haven’t used pinning before
Package: nmap Pin: release a=etch-backports Pin-Priority: 999
Now the system “remembers” that nmap is installed from the backports repository and you don’t have to worry about it anymore, nice.
Posted by Hans-Henry Jakobsen