I'm running into an annoying situation that is rendering apt-get update almost unuseable. I have several packages that I installed from and want to maintain from source, but every time I apt-get update it tries to update them, which then either screws up the version, installs an unwanted package, or installs it twice.

Two for example:

Exim4. I'm running courier-imap and qmail, but apt wants to install exim4 which obviously isn't appreciated.

Clamav. I maintain clam via source and don't want it installed by apt, yet it insists on including it in the packages to be upgraded.

If anyone can tell me on how to prevent apt from checking and upgrading specific packages I'd sure appreciate it.

The easiest way IMHO is using Synaptic. When the upgradeable packages are selected, you unselect the unwanted upgrades. Not sure it'll work, never tried it...

Lock the package either by using "pinning" or simply by selecting it in Synaptic>Package>Lock version.

I was under the impression that Synaptic is a GUI package manager. If that's the case it won't help me, as this is a command line server and doesn't have any X installed.

Any example of pinning?

Apt-Pinning for Beginners
http://jaqque.sbih.org/kplug/apt-pinning.html

Using APT with more than 2 sources
http://www.argon.org/~roderick/apt-pinning.html

Pin the package similiarly to:
Package: libasound2
Pin: version 1.0.11-4
Pin-Priority: 1001

Thanks much, took some fooling around with, but that's exactly what I was looking for!