[DRE-maint] Bug#679606: ruby-hpricot and ruby-fast-xs: error when trying to install together

[Ralf Treinen]

Package: ruby-fast-xs,ruby-hpricot
Version: ruby-fast-xs/0.8.0-2
Version: ruby-hpricot/0.8.6-2
Severity: serious
User: treinen at debian.org
Usertags: edos-file-overwrite

Date: 2012-06-30
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!
  libffi5 libreadline5 libyaml-0-2 libruby1.8 libruby1.9.1 ruby1.9.1 ruby
  ruby-fast-xs ruby-hpricot
Authentication warning overridden.
Can not write log, openpty() failed (/dev/pts not mounted?)
Selecting previously unselected package libffi5:amd64.
(Reading database ... 10722 files and directories currently installed.)
Unpacking libffi5:amd64 (from .../libffi5_3.0.10-3_amd64.deb) ...
Selecting previously unselected package libreadline5:amd64.
Unpacking libreadline5:amd64 (from .../libreadline5_5.2-11_amd64.deb) ...
Selecting previously unselected package libyaml-0-2:amd64.
Unpacking libyaml-0-2:amd64 (from .../libyaml-0-2_0.1.4-2_amd64.deb) ...
Selecting previously unselected package libruby1.8.
Unpacking libruby1.8 (from .../libruby1.8_1.8.7.358-4_amd64.deb) ...
Selecting previously unselected package libruby1.9.1.
Unpacking libruby1.9.1 (from .../libruby1.9.1_1.9.3.194-1_amd64.deb) ...
Selecting previously unselected package ruby1.9.1.
Unpacking ruby1.9.1 (from .../ruby1.9.1_1.9.3.194-1_amd64.deb) ...
Selecting previously unselected package ruby.
Unpacking ruby (from .../apt/archives/ruby_4.9_all.deb) ...
Selecting previously unselected package ruby-fast-xs.
Unpacking ruby-fast-xs (from .../ruby-fast-xs_0.8.0-2_amd64.deb) ...
Selecting previously unselected package ruby-hpricot.
Unpacking ruby-hpricot (from .../ruby-hpricot_0.8.6-2_amd64.deb) ...
dpkg: error processing /var/cache/apt/archives/ruby-hpricot_0.8.6-2_amd64.deb (--unpack):
 trying to overwrite '/usr/lib/ruby/vendor_ruby/1.9.1/x86_64-linux/fast_xs.so', which is also in package ruby-fast-xs 0.8.0-2
Processing triggers for man-db ...
Errors were encountered while processing:
 /var/cache/apt/archives/ruby-hpricot_0.8.6-2_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 sid/amd64, which may be
slightly out of sync):

  /usr/lib/ruby/vendor_ruby/1.8/x86_64-linux/fast_xs.so
  /usr/lib/ruby/vendor_ruby/1.9.1/x86_64-linux/fast_xs.so

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/.