[Cloud-packages] Bug#725663: python-uritemplate and python-googleapi: error when trying to install together

[Ralf Treinen]

Package: python-googleapi,python-uritemplate
Version: python-googleapi/1.2-1
Version: python-uritemplate/0.5.2-1
Severity: serious
User: treinen at debian.org
Usertags: edos-file-overwrite

Date: 2013-10-07
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!
  libexpat1 libffi6 libpython2.7-minimal python2.7-minimal mime-support
  libpython2.7-stdlib python2.7 python-minimal libpython-stdlib python
  python-uritemplate openssl ca-certificates python-httplib2 python-googleapi
Preconfiguring packages ...
Authentication warning overridden.
Selecting previously unselected package libexpat1:amd64.
(Reading database ... 10879 files and directories currently installed.)
Unpacking libexpat1:amd64 (from .../libexpat1_2.1.0-4_amd64.deb) ...
Selecting previously unselected package libffi6:amd64.
Unpacking libffi6:amd64 (from .../libffi6_3.0.13-4_amd64.deb) ...
Selecting previously unselected package libpython2.7-minimal:amd64.
Unpacking libpython2.7-minimal:amd64 (from .../libpython2.7-minimal_2.7.5-8_amd64.deb) ...
Selecting previously unselected package python2.7-minimal.
Unpacking python2.7-minimal (from .../python2.7-minimal_2.7.5-8_amd64.deb) ...
Selecting previously unselected package mime-support.
Unpacking mime-support (from .../mime-support_3.54_all.deb) ...
Selecting previously unselected package libpython2.7-stdlib:amd64.
Unpacking libpython2.7-stdlib:amd64 (from .../libpython2.7-stdlib_2.7.5-8_amd64.deb) ...
Selecting previously unselected package python2.7.
Unpacking python2.7 (from .../python2.7_2.7.5-8_amd64.deb) ...
Selecting previously unselected package python-minimal.
Unpacking python-minimal (from .../python-minimal_2.7.5-5_amd64.deb) ...
Selecting previously unselected package libpython-stdlib:amd64.
Unpacking libpython-stdlib:amd64 (from .../libpython-stdlib_2.7.5-5_amd64.deb) ...
Selecting previously unselected package python.
Unpacking python (from .../python_2.7.5-5_amd64.deb) ...
Selecting previously unselected package python-uritemplate.
Unpacking python-uritemplate (from .../python-uritemplate_0.5.2-1_all.deb) ...
Selecting previously unselected package openssl.
Unpacking openssl (from .../openssl_1.0.1e-3_amd64.deb) ...
Selecting previously unselected package ca-certificates.
Unpacking ca-certificates (from .../ca-certificates_20130906_all.deb) ...
Selecting previously unselected package python-httplib2.
Unpacking python-httplib2 (from .../python-httplib2_0.8-2_all.deb) ...
Selecting previously unselected package python-googleapi.
Unpacking python-googleapi (from .../python-googleapi_1.2-1_all.deb) ...
dpkg: error processing /var/cache/apt/archives/python-googleapi_1.2-1_all.deb (--unpack):
 trying to overwrite '/usr/share/pyshared/uritemplate/__init__.py', which is also in package python-uritemplate 0.5.2-1
Processing triggers for man-db ...
Errors were encountered while processing:
 /var/cache/apt/archives/python-googleapi_1.2-1_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/lib/python2.7/dist-packages/uritemplate/__init__.py
  /usr/share/pyshared/uritemplate/__init__.py

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/.