[Pkg-haskell-maintainers] Bug#679611: cabal-debian and haskell-debian-utils: error when trying to install together

[Ralf Treinen]

Package: haskell-debian-utils,cabal-debian
Version: haskell-debian-utils/3.64-2
Version: cabal-debian/1.25-1
Severity: serious
User: treinen at debian.org
Usertags: edos-file-overwrite

Date: 2012-06-30
Architecture: amd64
Distribution: testing

Hi,

automatic installation tests of packages that share a file and at the
same time do not conflict by their package dependency relationships has
detected the following problem:


WARNING: The following packages cannot be authenticated!
  libffi5 libgmp10 cabal-debian haskell-debian-utils
Authentication warning overridden.
Can not write log, openpty() failed (/dev/pts not mounted?)
Selecting previously unselected package libffi5:amd64.
(Reading database ... 10706 files and directories currently installed.)
Unpacking libffi5:amd64 (from .../libffi5_3.0.10-3_amd64.deb) ...
Selecting previously unselected package libgmp10:amd64.
Unpacking libgmp10:amd64 (from .../libgmp10_2%3a5.0.5+dfsg-2_amd64.deb) ...
Selecting previously unselected package cabal-debian.
Unpacking cabal-debian (from .../cabal-debian_1.25-1_amd64.deb) ...
Selecting previously unselected package haskell-debian-utils.
Unpacking haskell-debian-utils (from .../haskell-debian-utils_3.64-2_amd64.deb) ...
dpkg: error processing /var/cache/apt/archives/haskell-debian-utils_3.64-2_amd64.deb (--unpack):
 trying to overwrite '/usr/share/man/man1/cabal-debian.1.gz', which is also in package cabal-debian 1.25-1
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
Processing triggers for man-db ...
Errors were encountered while processing:
 /var/cache/apt/archives/haskell-debian-utils_3.64-2_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)


This is a serious bug as it makes installation fail, and violates
sections 7.6.1 and 10.1 of the policy. An optimal solution would
consist in only one of the packages installing that file, and renaming
or removing the file in the other package. Depending on the
circumstances you might also consider Replace relations or file
diversions. If the conflicting situation cannot be resolved then, as a
last resort, the two packages have to declare a mutual
Conflict. Please take into account that Replaces, Conflicts and
diversions should only be used when packages provide different
implementations for the same functionality.

Here is a list of files that are known to be shared by both packages
(according to the Contents file for testing/amd64, which may be
slightly out of sync):

  /usr/share/man/man1/cabal-debian.1.gz

This bug has been filed against both packages. If you, the maintainers of
the two packages in question, have agreed on which of the packages will
resolve the problem please reassign the bug to that package. You may then
also register in the BTS that the other package is affected by the bug.

-Ralf.

PS: for more information about the detection of file overwrite errors
of this kind see http://edos.debian.net/file-overwrites/.