[Bug 1795898] Update Released

[Łukasz Zemczak]

The verification of the Stable Release Update for update-manager has
completed successfully and the package has now been released to
-updates.  Subsequently, the Ubuntu Stable Release Updates Team is being
unsubscribed and will not receive messages about this bug report.  In
the event that you encounter a regression using the package from
-updates please report a new bug using ubuntu-bug and tag the bug report
regression-update so we can easily find any regressions.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to update-manager in Ubuntu.
https://bugs.launchpad.net/bugs/1795898

Title:
  TypeError: _action_done() got an unexpected keyword argument
  'trans_failed'

Status in update-manager package in Ubuntu:
  Fix Released
Status in update-manager source package in Bionic:
  Fix Committed

Bug description:
  [Impact]

  Lazy imports made update-manager crash when an update-manager
  update changed the backend API and an updated incompatible backend
  was loaded to the not updated running update-manager process.

  The issue causes crashes upon update-manager updates harming the
  upgrade experience for users.

  The fix avoids lazy loading of the backend modules but still honors
  the backend selection options.

  [Test Case]

  1. Start with a fully upgraded system and downgrade a few packages to let u-m upgrade them:
  $ sudo eatmydata apt install -y --allow-downgrades  gnome-software=3.28.1-0ubuntu4 gnome-software-common=3.28.1-0ubuntu4

  2. Start u-m with:
   $ update-manager --no-update

  3. Make a syntax error in /usr/lib/python3/dist-
  packages/UpdateManager/backend/InstallBackendAptdaemon.py

  4. Press "Install Now" on u-m GUI.
   The fixed u-m will successfully perform the installation, the unfixed one will fail with SyntaxError.

  [Regression Potential]

  Wrong changes to the backend import/selection logic could make u-m
  unable to find the available backends, but in my testing the fixed
  version could properly find both aptdaemon and synaptic when they were
  present.

  [Original Bug Text]
   
  Traceback (most recent call last):
    File "/usr/lib/python3/dist-packages/UpdateManager/backend/InstallBackendAptdaemon.py", line 242, in _on_finished
      trans_failed=trans_failed)
  TypeError: _action_done() got an unexpected keyword argument 'trans_failed'

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1795898/+subscriptions