[Debian-med-packaging] Bug#592244: libvxl1-dev and libvarnish-dev: error when trying to install together

[Ralf Treinen]

Package: libvarnish-dev,libvxl1-dev
Version: libvarnish-dev/2.1.3-4
Version: libvxl1-dev/1.14.0-1
Severity: serious
User: treinen at debian.org
Usertags: edos-file-overwrite

Date: 2010-08-08
Architecture: amd64
Distribution: sid

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!
  libpcre3 libvarnish1 libvarnish-dev libvxl1.14 libvxl1-dev
Authentication warning overridden.
Can not write log, openpty() failed (/dev/pts not mounted?)
Selecting previously deselected package libpcre3.
(Reading database ... 12247 files and directories currently installed.)
Unpacking libpcre3 (from .../libpcre3_8.02-1.1_amd64.deb) ...
Selecting previously deselected package libvarnish1.
Unpacking libvarnish1 (from .../libvarnish1_2.1.3-4_amd64.deb) ...
Selecting previously deselected package libvarnish-dev.
Unpacking libvarnish-dev (from .../libvarnish-dev_2.1.3-4_amd64.deb) ...
Selecting previously deselected package libvxl1.14.
Unpacking libvxl1.14 (from .../libvxl1.14_1.14.0-1_amd64.deb) ...
Selecting previously deselected package libvxl1-dev.
Unpacking libvxl1-dev (from .../libvxl1-dev_1.14.0-1_amd64.deb) ...
dpkg: error processing /var/cache/apt/archives/libvxl1-dev_1.14.0-1_amd64.deb (--unpack):
 trying to overwrite '/usr/lib/libvcl.so', which is also in package libvarnish-dev 0:2.1.3-4
Processing triggers for man-db ...
Errors were encountered while processing:
 /var/cache/apt/archives/libvxl1-dev_1.14.0-1_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
cow-shell unlink .ilist: No such file or directory


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 sid/amd64, which may be
slightly out of sync):

  /usr/lib/libvcl.so

This bug is assigned to 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.

-Ralf.

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