Dose-Debcheck: Not Installable Packages

Results of the different checks

These checks are run daily on qa.debian.org:

What it means

We call a package installable if all its (recursive) dependencies can be satisfied without violating any conflicts. More precisely, a package p is called installable in a package repository D if there is a subset S of D containing p, and such that for each package in S

Alternative dependencies and virtual packages are taken into account, as well as other aspects of Debian package relations like the fact that a versioned dependency is not matched by a virtual package, or the fact that there are no self-conflicts via a provided virtual package. Packages from a so-called background can be used to satisfy dependencies, but we are not interested in installability of background packages per se.

In case a package exists with multiple versions in a distribution (which may happen in the unstable distribution), only the latest version is checked for installability.

How it is done

The set of not installable packages is computed using the dose-debcheck tool available in the dose-distcheck package, the successor of the previously used edos-debcheck tool.

Filing bugs

Whether a not-installable package deserves a bug report depends on the situation:
  1. All packages in the stable and testing distribution should be installable, with the exception of packages with Architecture=all. The reason for the latter exception is that these packages are usually available for each architecture, regardless of the fact whether their dependencies can be satisfied on that architecture or not. However, when a package with Architecture=all is not installable on any architecture then something is wrong.

    Normally, a bug should be filed only when a package is not installable on any architecture (regardless of the value of the Architecture field of the package). In any case, the situation should be investigated before filing a bug. For instance, it may be the case that a package is installable only in a multi-arch setting.

  2. By its very nature, the unstable distribution is expected to have many packages that are not installable. However, this should normally be temporary. That means that, in addition to the above restrictions:
    • Bugs should be filed only when the problem exists over an extended period of time (say, 1 month).
    • Bugs should not be filed when a package is involved in a transition as these cases are already monitored.
This policy has been announced and discussed in this thread. Detected bugs are marked in teh BTS with user treinen@debian.org and usertag edos-uninstallable.

Related checks

See also the check for outdated packages which is much more restricted, but is also much more likely to pinpoint the source of a non-installabity.

Further reading