do-release-upgrade 18 to 20 LTS failed

[Cliff Kotnik]

I started the release upgrade. It ran for a few minutes and then terminated with

Calculating the changes
Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

If none of this applies, then please report this bug using the
command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. If
you want to investigate this yourself the log files in
'/var/log/dist-upgrade' will contain details about the upgrade.
Specifically, look at 'main.log' and 'apt.log'.

Restoring original system state
Aborting

I need help resolving this.
Cliff

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.44
ProcVersionSignature: Ubuntu 4.15.0-142.146-generic 4.15.18
Uname: Linux 4.15.0-142-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.9-0ubuntu7.23
Architecture: amd64
CrashDB: ubuntu
Date: Fri Apr 23 10:48:01 2021
InstallationDate: Installed on 2012-05-16 (3263 days ago)
InstallationMedia: Ubuntu-Server 12.04 LTS "Precise Pangolin" - Release amd64 (20120424.1)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2021-04-23 (0 days ago)

[Brian Murray (brian-murray)]

Thanks for taking the time to report this upgrade failure. There is currently a new version of the release upgrader available in -proposed which may resolve the error you've encountered. Please run the following command to test the new version of the upgrader:

  do-release-upgrade -p

Please lets us know the results in this bug report. Thanks again and good luck!

[Cliff Kotnik (clkotnik)]

Per Brian's instructions of 5-14 I performed the upgrade with the "-p" option. The upgrade performed as expected and my system is now on release 20.

thanks very much for the quick response.
Cliff