[Bug 1045926] Re: python-minimal dependency blocks LTS upgrade from lucid to precise

[Bill Hammond]

Python is so intertwined with package management that the package
management suite should use its own private version of python that is
invariant across all releases.  (The situation seems to be parallel to
that which led sagemath to maintain its own private version of python.)

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to update-manager-core in Ubuntu.
https://bugs.launchpad.net/bugs/1045926

Title:
  python-minimal dependency blocks LTS upgrade from lucid to precise

Status in “update-manager-core” package in Ubuntu:
  New

Bug description:
  python-minimal is an essential package.  In "precise" python-minimal
  is version 2.7.3, which has dependencies:  python2.7-minimal (>=
  2.7.3), dpkg (>= 1.13.20).  The package python2.7-minimal in "precise"
  is version 2.7.3 (and it also appears in precise-updates).
  python2.7-minimal has dependencies: libc6 (>= 2.15), libgcc1 (>=
  1:4.1.1), libssl1.0.0 (>= 1.0.0), zlib1g (>= 1:1.2.0), python-minimal
  (>= 2.6.6-3+squeeze1).  The python-minimal dependency cannot be met
  from a fully updated "lucid" where the version of python-minimal is
  2.6.5-0ubuntu1.

  Furthermore:

  1. Ubuntu release: 10.04.4LTS partially upgraded to 12.04, presently
  stuck in between due to multiple failures in the post first-point-
  release upgrade action triggered with update manager.

  2. Package version: see above.  apt-cache policy outputs for 3 packages:
  python-minimal:
    Installed: 2.6.5-0ubuntu1
    Candidate: 2.7.3-0ubuntu2
    Version table:
       2.7.3-0ubuntu2 0
          500 http://us.archive.ubuntu.com/ubuntu/ precise/main Packages
   *** 2.6.5-0ubuntu1 0
          100 /var/lib/dpkg/status
  python2.6-minimal:
    Installed: 2.6.5-1ubuntu6
    Candidate: 2.6.5-1ubuntu6
    Version table:
   *** 2.6.5-1ubuntu6 0
          100 /var/lib/dpkg/status
  python2.7-minimal:
    Installed: 2.7.3-0ubuntu3.1
    Candidate: 2.7.3-0ubuntu3.1
    Version table:
   *** 2.7.3-0ubuntu3.1 0
          500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/main Packages
          100 /var/lib/dpkg/status
       2.7.3-0ubuntu3 0
          500 http://us.archive.ubuntu.com/ubuntu/ precise/main Packages

  N.B. aptitude reports the state of python2.7-minimal as "unpacked".

  3. What expected to happen: N/A

  4. What happened: N/A

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/update-manager-core/+bug/1045926/+subscriptions