Bug#559194: Unused automatically installed packages don't get removed on upgrade

[Uwe Storbeck <uwe@ibr.ch>]

On Mar 26, David Kalnischkies wrote:
> policy says about priority required:
> "Packages which are necessary for the proper functioning of the system
> (usually, this means that dpkg functionality depends on these packages).

We are talking about obsolete packages. These packages are not
required anymore by the system. Actually they are not even used
anymore and are garbage only.

> I wouldn't consider this a bug in APT and co as its way easier to
> break your system than it is useful in helping cleaning up…

apt knows when a package is obsolete and not used anymore. So it
could remove those packages with no harm to the system.

Debian has a good reputation for long term stability and
upgradability. That's why there should be a standard mechanism to
get rid of old, obsolete packages which are not used anymore,
even when they have been required for the system at some point.

I do not say that apt and co have to handle this case. It also
could be handled by another mechanism (e.g. by transitional
packages which reduce the priority when a packages is not
required by the system anymore). But it should be handled at all.

Regards

Uwe