ubuntu-release-upgrader crashed with SystemError: E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

Here's the Traceback:

Traceback (most recent call last):
  File "/tmp/ubuntu-release-upgrader-_he31ans/bionic", line 8, in <module>
    sys.exit(main())
  File "/tmp/ubuntu-release-upgrader-_he31ans/DistUpgrade/DistUpgradeMain.py", line 238, in main
    if app.run():
  File "/tmp/ubuntu-release-upgrader-_he31ans/DistUpgrade/DistUpgradeController.py", line 2017, in run
    return self.fullUpgrade()
  File "/tmp/ubuntu-release-upgrader-_he31ans/DistUpgrade/DistUpgradeController.py", line 1958, in fullUpgrade
    self.cache["libc6"].mark_install()
  File "/usr/lib/python3/dist-packages/apt/package.py", line 1309, in mark_install
    fixer.resolve(True)
SystemError: E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

The reports in the Ubuntu Error Tracker aren't particularly informative about what may be causing this, the only clues in them are Dependencies.txt and I didn't seen anything strange in there.

Status changed to 'Confirmed' because the bug affects multiple users.

This bug was fixed in the package ubuntu-release-upgrader - 1:18.10.10

---------------
ubuntu-release-upgrader (1:18.10.10) cosmic; urgency=medium

  [ Harald Sitter ]
  * DistUpgradeViewKDE.py:
    - exitMainLoop is now exitMainLoopMidFlight to make it clearer that
      it is run while the app is still running. it's a hack and not
      the actual exit point
    - inhibit kscreenlocker while the UI is up to prevent the lock screen
      from breaking during upgrades and then complain to the user

  [ Brian Murray ]
  * DistUpgradeQuirks.py: add a quirk which checks for an apt architecture
    of i386 and prevents the upgrade as the architecture may be dropped.
  * DistUpgradeController.py: If the attempt to only upgrade libc6 ends up
    creating an issue with apt's problem resolver try the full upgrade. This
    is what would have happened before the fix for bug 1766890. (LP: #1787649)

 -- Brian Murray <email address hidden> Fri, 31 Aug 2018 15:36:32 -0700

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

Accepted ubuntu-release-upgrader into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/ubuntu-release-upgrader/1:18.04.26 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 and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. 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!

I upgraded an Ubuntu 16.04 desktop system using release-upgrader version 18.04.26 to Ubuntu 18.04 without any issues today.

I also upgraded an Ubuntu 16.04 system with ubuntu-server installed using release-upgrader version 18.04.26 to Ubuntu 18.04 and there were no issues.

And I upgraded an Ubuntu 16.04 cloud image in lxc using release-upgrader version 18.04.26 to Ubuntu 18.04 and encountered no problems.

I went through crash reports in the Ubuntu Error Tracker today about ubuntu-release-upgrader and didn't see any about the new version of dist-upgrader with that looked like the Traceback this bug is supposed to fix so I'm setting it to v-done.

This bug was fixed in the package ubuntu-release-upgrader - 1:18.04.26

---------------
ubuntu-release-upgrader (1:18.04.26) bionic; urgency=medium

  * DistUpgradeController.py: If the attempt to only upgrade libc6 ends up
    creating an issue with apt's problem resolver try the full upgrade. This
    is what would have happened before the fix for bug 1766890. (LP: #1787649)

 -- Brian Murray <email address hidden> Wed, 05 Sep 2018 08:37:51 -0700

The verification of the Stable Release Update for ubuntu-release-upgrader 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.