[SRU] /usr/bin/update-manager:TypeError:_on_finished:_action_done:get_deb2snap_dups:_on_finished:_action_done:get_deb2snap_dups

Here's the Traceback:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/InstallBackendAptdaemon.py", line 236, in _on_finished
    self._action_done(action,
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/__init__.py", line 319, in _action_done
    self.window_main.duplicate_packages = self.get_deb2snap_dups()
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/__init__.py", line 125, in get_deb2snap_dups
    if (deb in cache and cache[deb].is_installed):
TypeError: argument of type 'NoneType' is not iterable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/InstallBackendAptdaemon.py", line 244, in _on_finished
    self._action_done(action,
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/__init__.py", line 319, in _action_done
    self.window_main.duplicate_packages = self.get_deb2snap_dups()
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/__init__.py", line 125, in get_deb2snap_dups
    if (deb in cache and cache[deb].is_installed):
TypeError: argument of type 'NoneType' is not iterable

This is reproducable by raising an AssertionError in the initialization of MyCache and looks like a problem with "UpdateManager/backend/__init__.py" carrying on when cache is set to None. Here are the lines of code I'm looking at:

        except Exception as e:
            logging.debug("error reading cache (%s)" % e)
            cache = None

Thanks for the info Brian. I’ll try prep a fix for this tomorrow.

This bug was fixed in the package update-manager - 1:20.04.12

---------------
update-manager (1:20.04.12) groovy; urgency=medium

  * Fix hang in apturl-gtk. (LP: #1874591)
  * Fix crash in snap updates when refreshing the cache fails. (LP: #1880987)

 -- Marcus Tomlinson <email address hidden> Thu, 28 May 2020 10:11:51 +0100

Hello errors.ubuntu.com, or anyone else affected,

Accepted update-manager into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/update-manager/1:20.04.10.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Looking at the bucket for this crash at errors.ubuntu.com I only see a couple of instances of this crash with the version of the package from -proposed and those are likely noise. So I'm setting this to verification-done.

This bug was fixed in the package update-manager - 1:20.04.10.1

---------------
update-manager (1:20.04.10.1) focal; urgency=medium

  * UpdateManager/UpdateManager.py: when refreshing the cache and encountering
    an error return rather than trying to use the undefined cache which causes
    crashes. Additionally, don't present the dialog with a "Try Again" button
    which won't do anything. (LP: #1826213)
  * Fix hang in apturl-gtk. (LP: #1874591)
  * Fix crash in snap updates when refreshing the cache fails. (LP: #1880987)

 -- Brian Murray <email address hidden> Wed, 03 Jun 2020 10:18:00 -0700

The verification of the Stable Release Update for update-manager has completed successfully and the package is now being 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.