ubuntu upgrade from 18.04 to 20.04 fails due to dependency collision

[Simon]

When trying to upgrade to 20.04 via

$ sudo do-release-upgrade -d'

the process aborts while calculating dependencies. The first error I can spot in /var/log/dist-upgrade/main.log is

ERROR Dist-upgrade failed: 'Broken packages after upgrade: colord'

but I am unsure how to dig deeper to find out what exactly is going wrong here. Does someone have a hint where to look next?

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.38
ProcVersionSignature: Ubuntu 4.15.0-115.116-generic 4.15.18
Uname: Linux 4.15.0-115-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.17
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Sat Aug 29 11:45:50 2020
InstallationDate: Installed on 2014-05-16 (2296 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2020-08-29 (0 days ago)

[Brian Murray (brian-murray)]

Reviewing the files from your upgrade attempt you seem to have enabled a PPA that provides Xorg and python packages. This will prevent the upgrade as that PPA contains packages which generate failures when trying to calculate the upgrade. You can revert the PPA by installing the ppa-purge package from the official Ubuntu archive and then running 'sudo ppa-purge ppa:oibaf/graphics-drivers'. After that you can try upgrading again and if it still fails open a new bug report. Thanks and good luck!

[Simon (simonkuehling)]

Thanks Brian,
your suggestion actually did the trick!

The further upgrade was a success after that.

- Simon