Comment 13 for bug 603852

Firstly, this is not an aptitude bug. Aptitude relies on APT to
determine the order in which to install/configure dependencies.
Let us not engage in reassign-pong until a clear culprit is determined.

User lool writes:
> python2.6 correctly depends on python2.6-minimal (=
> ${binary:Version}), yet python2.6 was unpacked before
> python2.6-minimal.

Unpacked packages are not configured. The order of unpacking in this
case is rather irrelevent. It is the order of configuration which is
important however, the error occurs before any configuration is
attempted.

The error is:
> Processing triggers for python-gmenu ...
> Rebuilding /usr/share/applications/desktop.en_US.utf8.cache...
> Traceback (most recent call last):
> File "/usr/sbin/update-python-modules", line 11, in <module>
> import sys,os,shutil
> ImportError: No module named shutil
> dpkg: error processing python-gmenu (--unpack):
> subprocess installed post-installation script returned error exit status 1

Correct me if I am wrong with what follows.

Given that, at this point:
  - python2.6, python-minimal are both unpacked, but deconfigred; and
  - module shutil has changed places during this particular upgrade;

it is not safe to run any python code until these packages are
reconfigured. It is common practice to not disable running of python
code during a normal python upgrade because the packages are
previously installed and thus "working". This particular upgrade
causes the python system to not work for some specific modules.

The updated set of python packages in this case should be disabling
the running of python code until they are reconfigured.

To diagnose specifically what is going on here it may be necessary to
examine the particular .deb files involved:

libpython2.6_2.6.5+20100616-1ubuntu2_i386.deb
libpython2.6_2.6.5+20100706-1ubuntu1_i386.deb
python2.6_2.6.5+20100616-1ubuntu2_i386.deb
python2.6_2.6.5+20100706-1ubuntu1_i386.deb
python_2.6.5-5ubuntu3_all.deb
python_2.6.5-5ubuntu4_all.deb
python-minimal_2.6.5-5ubuntu3_all.deb
python-minimal_2.6.5-5ubuntu4_all.deb

and also the python-gmenu packages from around the same time.

Is there a service for Ubuntu similar to snapshot.d.n which could
provide such old files?