This is a quick Debian recipe, mainly as a note to myself, but that can be useful to people out there: what if I wanted instruct APT to never install a particular package? This may lead to wonder whether there is a really sane use case for that, and I can think at least about two:

• For server setups, to prevent certain packages like the X11 window system to be installed.
• To avoid dependencies on deprecated packages.

The later is my use-case for today: HAL is nowadays deprecated, being DeviceKit and udev the new shiny stuff that everybody should use in a modern GNU/Linux desktop. My laptop is running Sid, so ideally there shouldn’t be HAL packages in it, should they?

In short, the idea is to pin packages with a lower-than-zero priority. If packages were already installed, they will not be upgraded by APT. For packages that are not installed, this will instruct APT to avoid them as much as possible. This is how my pinning for HAL looks like:

  % cat /etc/apt/preferences.d/nohal
  Package: hal
  Pin: version *
  Pin-Priority: -100

  Package: hal-info
  Pin: version *
  Pin-Priority: -100

  Package: libhal1
  Pin: version *
  Pin-Priority: -100

…and that’s it :-D

Anyway, I still prefer package masking or setting USE="-hal" in Gentoo, it’s cleaner and meaner.