Upgrading from 2018.04 to to 2020.04 fails. Tried disabling repos, uninstalling things etc.

[Tomas Mannerstedt]

$ cat /var/log/dist-upgrade/main.log
2020-10-07 20:52:52,701 INFO Using config files '['./DistUpgrade.cfg.bionic']'
2020-10-07 20:52:52,701 INFO uname information: 'Linux halx 5.4.0-48-generic #52~18.04.1-Ubuntu SMP Thu Sep 10 12:50:22 UTC 2020 x86_64'
2020-10-07 20:52:53,193 INFO apt version: '1.6.12ubuntu0.1'
2020-10-07 20:52:53,193 INFO python version: '3.6.9 (default, Jul 17 2020, 12:50:27)
[GCC 8.4.0]'
2020-10-07 20:52:53,198 INFO release-upgrader version '20.04.25' started
2020-10-07 20:52:53,211 INFO locale: 'en_US' 'UTF-8'
2020-10-07 20:52:53,263 INFO screen could not be run
2020-10-07 20:52:53,293 DEBUG Using 'DistUpgradeViewText' view
2020-10-07 20:52:53,338 DEBUG enable dpkg --force-overwrite
2020-10-07 20:52:53,367 DEBUG creating statefile: '/var/log/dist-upgrade/apt-clone_system_state.tar.gz'
2020-10-07 20:52:56,442 DEBUG lsb-release: 'bionic'
2020-10-07 20:52:56,442 DEBUG _pythonSymlinkCheck run
2020-10-07 20:52:56,443 DEBUG openCache()
2020-10-07 20:52:56,443 DEBUG quirks: running PreCacheOpen
2020-10-07 20:52:56,443 DEBUG running Quirks.PreCacheOpen
2020-10-07 20:52:57,532 DEBUG Comparing 5.4.0-47 with
2020-10-07 20:52:57,532 DEBUG Comparing 5.4.0-48 with 5.4.0-47
2020-10-07 20:52:57,729 DEBUG /openCache(), new cache size 99739
2020-10-07 20:52:57,729 DEBUG need_server_mode(): run in 'desktop' mode, (because of pkg 'ubuntu-desktop')
2020-10-07 20:52:57,729 DEBUG checkViewDepends()
2020-10-07 20:52:57,730 DEBUG running doUpdate() (showErrors=False)
2020-10-07 20:52:58,698 DEBUG openCache()
2020-10-07 20:52:59,760 DEBUG Comparing 5.4.0-47 with
2020-10-07 20:52:59,760 DEBUG Comparing 5.4.0-48 with 5.4.0-47
2020-10-07 20:52:59,978 DEBUG /openCache(), new cache size 99739
2020-10-07 20:52:59,979 DEBUG doPostInitialUpdate
2020-10-07 20:52:59,979 DEBUG quirks: running focalPostInitialUpdate
2020-10-07 20:52:59,979 DEBUG running Quirks.focalPostInitialUpdate
2020-10-07 20:53:01,714 DEBUG Snap core18 is installed
2020-10-07 20:53:01,911 DEBUG Snap gnome-3-34-1804 is installed
2020-10-07 20:53:01,913 DEBUG Snap gnome-3-34-1804 is not tracking the release channel
2020-10-07 20:53:02,230 DEBUG Snap gtk-common-themes is installed
2020-10-07 20:53:02,743 DEBUG Snap gnome-3-28-1804 is installed
2020-10-07 20:53:02,743 DEBUG Snap gnome-3-28-1804 is not tracking the release channel
2020-10-07 20:53:03,052 DEBUG Snap gnome-calculator is installed
2020-10-07 20:53:03,233 DEBUG Snap gnome-characters is installed
2020-10-07 20:53:03,564 DEBUG Snap gnome-logs is installed
2020-10-07 20:53:05,679 DEBUG MetaPkgs: ubuntu-desktop
2020-10-07 20:53:08,387 DEBUG Foreign:
2020-10-07 20:53:08,387 DEBUG Obsolete: gnome-subtitles synology-cloud-station
2020-10-07 20:53:08,387 DEBUG updateSourcesList()
2020-10-07 20:53:08,398 DEBUG rewriteSourcesList() with mirror_check
2020-10-07 20:53:08,398 DEBUG ['ubuntu-minimal', 'ubuntu-standard']
2020-10-07 20:53:08,398 DEBUG Checking pkg: ubuntu-minimal
2020-10-07 20:53:08,400 DEBUG Checking pkg: ubuntu-standard
2020-10-07 20:53:08,401 DEBUG examining: 'deb http://se.archive.ubuntu.com/ubuntu/ bionic main restricted'
2020-10-07 20:53:08,401 DEBUG verifySourcesListEntry: deb http://se.archive.ubuntu.com/ubuntu/ focal main restricted
2020-10-07 20:53:08,402 DEBUG url_downloadable: http://se.archive.ubuntu.com/ubuntu//dists/focal/Release
2020-10-07 20:53:08,402 DEBUG s='http' n='se.archive.ubuntu.com' p='/ubuntu//dists/focal/Release' q='' f=''
2020-10-07 20:53:08,611 DEBUG entry 'deb http://se.archive.ubuntu.com/ubuntu/ focal main restricted' updated to new dist
2020-10-07 20:53:08,612 DEBUG examining: 'deb http://se.archive.ubuntu.com/ubuntu/ bionic-updates main restricted'
2020-10-07 20:53:08,612 DEBUG entry 'deb http://se.archive.ubuntu.com/ubuntu/ focal-updates main restricted' updated to new dist
2020-10-07 20:53:08,612 DEBUG examining: 'deb http://se.archive.ubuntu.com/ubuntu/ bionic universe'
2020-10-07 20:53:08,613 DEBUG entry 'deb http://se.archive.ubuntu.com/ubuntu/ focal universe' updated to new dist
2020-10-07 20:53:08,613 DEBUG examining: 'deb http://se.archive.ubuntu.com/ubuntu/ bionic-updates universe'
2020-10-07 20:53:08,614 DEBUG entry 'deb http://se.archive.ubuntu.com/ubuntu/ focal-updates universe' updated to new dist
2020-10-07 20:53:08,614 DEBUG examining: 'deb http://se.archive.ubuntu.com/ubuntu/ bionic multiverse'
2020-10-07 20:53:08,615 DEBUG entry 'deb http://se.archive.ubuntu.com/ubuntu/ focal multiverse' updated to new dist
2020-10-07 20:53:08,615 DEBUG examining: 'deb http://se.archive.ubuntu.com/ubuntu/ bionic-updates multiverse'
2020-10-07 20:53:08,616 DEBUG entry 'deb http://se.archive.ubuntu.com/ubuntu/ focal-updates multiverse' updated to new dist
2020-10-07 20:53:08,616 DEBUG examining: 'deb http://se.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse'
2020-10-07 20:53:08,617 DEBUG entry 'deb http://se.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse' updated to new dist
2020-10-07 20:53:08,617 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu bionic-security main restricted'
2020-10-07 20:53:08,617 DEBUG verifySourcesListEntry: deb http://security.ubuntu.com/ubuntu focal main restricted
2020-10-07 20:53:08,618 DEBUG url_downloadable: http://security.ubuntu.com/ubuntu/dists/focal/Release
2020-10-07 20:53:08,618 DEBUG s='http' n='security.ubuntu.com' p='/ubuntu/dists/focal/Release' q='' f=''
2020-10-07 20:53:08,876 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security main restricted' updated to new dist
2020-10-07 20:53:08,876 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu bionic-security universe'
2020-10-07 20:53:08,877 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security universe' updated to new dist
2020-10-07 20:53:08,877 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu bionic-security multiverse'
2020-10-07 20:53:08,877 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security multiverse' updated to new dist
2020-10-07 20:53:08,881 DEBUG running doUpdate() (showErrors=True)
2020-10-07 20:53:44,943 DEBUG openCache()
2020-10-07 20:53:45,735 DEBUG Comparing 5.4.0-47 with
2020-10-07 20:53:45,735 DEBUG Comparing 5.4.0-48 with 5.4.0-47
2020-10-07 20:53:45,877 DEBUG /openCache(), new cache size 66441
2020-10-07 20:53:45,878 DEBUG need_server_mode(): run in 'desktop' mode, (because of pkg 'ubuntu-desktop')
2020-10-07 20:53:45,878 DEBUG quirks: running PreDistUpgradeCache
2020-10-07 20:53:45,878 DEBUG running Quirks.PreDistUpgradeCache
2020-10-07 20:53:45,878 INFO installing python-is-python2 because python-minimal was installed
2020-10-07 20:53:45,878 DEBUG Installing 'python-is-python2' (python-minimal was installed on the system)
2020-10-07 20:53:46,173 ERROR Dist-upgrade failed: 'E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.'
2020-10-07 20:53:46,174 DEBUG abort called
2020-10-07 20:53:46,175 DEBUG openCache()
2020-10-07 20:53:48,831 DEBUG Comparing 5.4.0-47 with
2020-10-07 20:53:48,831 DEBUG Comparing 5.4.0-48 with 5.4.0-47
2020-10-07 20:53:49,065 DEBUG /openCache(), new cache size 99739

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.38
ProcVersionSignature: Ubuntu 5.4.0-48.52~18.04.1-generic 5.4.60
Uname: Linux 5.4.0-48-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.18
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Wed Oct 7 21:12:45 2020
InstallationDate: Installed on 2019-07-12 (453 days ago)
InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2020-10-07 (0 days ago)

[Brian Murray (brian-murray)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1898152, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.