Install Non-RP Packages
From Roaring Penguin
Just add a standard Debian repository to:
/etc/apt/sources.list
For example:
deb http://http.us.debian.org/debian/ <version> main contrib non-free
How to find your <version> codename
Next, refresh the list of available packages via:
apt-get update
You want to add the specific packages ONLY via apt-get so, to verify it doesn't add anything that might clobber CanIt, you can do this first:
apt-get -s install package1 package2
Which just simulates the install so you can see what would be done, and then, for real:
apt-get install package1 package2
If you don't just add the packages needed, their versions of some packages conflict with ours. (Sendmail is a prime example - theirs doesn't know about MIMEDefang...)
Once the packages are installed, re-edit /etc/apt/sources.list to comment out the Debian repository, then refresh the package list again via:
apt-get update