[Python-modules-team] Bug#567378: python-markdown: error when trying to install together with libtext-markdown-perl or markdown

[Ralf Treinen]

Package: python-markdown
Version: 2.0.3-1
Severity: serious
User: treinen at debian.org
Usertags: edos-file-overwrite

Date: 2010-01-28
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!
  markdown python-markdown
W: cowdancer: unsupported operation flock, read-only open and fchown/fchmod/flock are not supported: tried openning dev:inode of 2055:5408144
W: cowdancer: unsupported operation flock, read-only open and fchown/fchmod/flock are not supported: tried openning dev:inode of 2055:5407760
W: cowdancer: unsupported operation flock, read-only open and fchown/fchmod/flock are not supported: tried openning dev:inode of 2055:5408145
Authentication warning overridden.
Can not write log, openpty() failed (/dev/pts not mounted?)
Selecting previously deselected package markdown.
(Reading database ... 12276 files and directories currently installed.)
Unpacking markdown (from .../markdown_1.0.1-7_all.deb) ...
Selecting previously deselected package python-markdown.
Unpacking python-markdown (from .../python-markdown_2.0.3-1_all.deb) ...
dpkg: error processing /var/cache/apt/archives/python-markdown_2.0.3-1_all.deb (--unpack):
 trying to overwrite '/usr/bin/markdown', which is also in package markdown 0:1.0.1-7
Processing triggers for man-db ...
W: cowdancer: unsupported operation flock, read-only open and fchown/fchmod/flock are not supported: tried openning dev:inode of 2055:5408144
W: cowdancer: unsupported operation flock, read-only open and fchown/fchmod/flock are not supported: tried openning dev:inode of 2055:5407760
W: cowdancer: unsupported operation flock, read-only open and fchown/fchmod/flock are not supported: tried openning dev:inode of 2055:5408145
Errors were encountered while processing:
 /var/cache/apt/archives/python-markdown_2.0.3-1_all.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/bin/markdown

The same problem occurs in conjunction with the package libtext-markdown-perl:


Selecting previously deselected package python-markdown.
Unpacking python-markdown (from .../python-markdown_2.0.3-1_all.deb) ...
dpkg: error processing /var/cache/apt/archives/python-markdown_2.0.3-1_all.deb (--unpack):
 trying to overwrite '/usr/bin/markdown', which is also in package libtext-markdown-perl 0:1.0.26-1

Again, the file /usr/bin/markdown is common to both packages. Since
the bug does *not* occur for the conjunction of markdown and
libtext-markdown-perl, I assume that the python-markdown package is at
fault here. If this is not the case then please reassign the bug
report accordingly.

-Ralf.

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