cannot upgrade ubuntu 20.04

[stef]

here are the last bits of main.log

2021-01-28 16:19:57,078 DEBUG Obsolete: cuda-command-line-tools-10-2 cuda-compiler-10-2 cuda-cudart-10-2 cuda-cudart-dev-10-2 cuda-cufft-10-2 cuda-cufft-dev-10-2 cuda-cuobjdump-10-2 cuda-cupti-10-2 cuda-cupti-dev-10-2 cuda-curand-10-2 cuda-curand-dev-10-2 cuda-cusolver-10-2 cuda-cusolver-dev-10-2 cuda-cusparse-10-2 cuda-cusparse-dev-10-2 cuda-documentation-10-2 cuda-driver-dev-10-2 cuda-gdb-10-2 cuda-libraries-10-2 cuda-libraries-dev-10-2 cuda-license-10-2 cuda-memcheck-10-2 cuda-misc-headers-10-2 cuda-npp-10-2 cuda-npp-dev-10-2 cuda-nsight-10-2 cuda-nsight-compute-10-2 cuda-nsight-systems-10-2 cuda-nvcc-10-2 cuda-nvdisasm-10-2 cuda-nvgraph-10-2 cuda-nvgraph-dev-10-2 cuda-nvjpeg-10-2 cuda-nvjpeg-dev-10-2 cuda-nvml-dev-10-2 cuda-nvprof-10-2 cuda-nvprune-10-2 cuda-nvrtc-10-2 cuda-nvrtc-dev-10-2 cuda-nvtx-10-2 cuda-nvvp-10-2 cuda-repo-ubuntu1804-10-2-local-10.2.89-440.33.01 cuda-samples-10-2 cuda-sanitizer-api-10-2 cuda-toolkit-10-2 cuda-tools-10-2 cuda-visual-tools-10-2 libcublas-dev libcublas10 lur-command nsight-compute-2019.5.0 nsight-systems-2019.5.2 piper sublime-text zoneminder zoneminder-doc
2021-01-28 16:19:57,079 DEBUG updateSourcesList()
2021-01-28 16:19:57,088 DEBUG rewriteSourcesList() with mirror_check
2021-01-28 16:19:57,089 DEBUG ['ubuntu-minimal', 'ubuntu-standard']
2021-01-28 16:19:57,089 DEBUG Checking pkg: ubuntu-minimal
2021-01-28 16:19:57,090 DEBUG Checking pkg: ubuntu-standard
2021-01-28 16:19:57,092 DEBUG examining: 'deb http://us.archive.ubuntu.com/ubuntu/ bionic main restricted'
2021-01-28 16:19:57,092 DEBUG verifySourcesListEntry: deb http://us.archive.ubuntu.com/ubuntu/ focal main restricted
2021-01-28 16:19:57,092 DEBUG url_downloadable: http://us.archive.ubuntu.com/ubuntu//dists/focal/Release
2021-01-28 16:19:57,092 DEBUG s='http' n='us.archive.ubuntu.com' p='/ubuntu//dists/focal/Release' q='' f=''
2021-01-28 16:19:57,114 DEBUG entry 'deb http://us.archive.ubuntu.com/ubuntu/ focal main restricted' updated to new dist
2021-01-28 16:19:57,114 DEBUG examining: 'deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates main restricted'
2021-01-28 16:19:57,114 DEBUG entry 'deb http://us.archive.ubuntu.com/ubuntu/ focal-updates main restricted' updated to new dist
2021-01-28 16:19:57,114 DEBUG examining: 'deb http://us.archive.ubuntu.com/ubuntu/ bionic universe'
2021-01-28 16:19:57,114 DEBUG entry 'deb http://us.archive.ubuntu.com/ubuntu/ focal universe' updated to new dist
2021-01-28 16:19:57,114 DEBUG examining: 'deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates universe'
2021-01-28 16:19:57,114 DEBUG entry 'deb http://us.archive.ubuntu.com/ubuntu/ focal-updates universe' updated to new dist
2021-01-28 16:19:57,114 DEBUG examining: 'deb http://us.archive.ubuntu.com/ubuntu/ bionic multiverse'
2021-01-28 16:19:57,115 DEBUG entry 'deb http://us.archive.ubuntu.com/ubuntu/ focal multiverse' updated to new dist
2021-01-28 16:19:57,115 DEBUG examining: 'deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates multiverse'
2021-01-28 16:19:57,115 DEBUG entry 'deb http://us.archive.ubuntu.com/ubuntu/ focal-updates multiverse' updated to new dist
2021-01-28 16:19:57,115 DEBUG examining: 'deb http://us.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse'
2021-01-28 16:19:57,115 DEBUG entry 'deb http://us.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse' updated to new dist
2021-01-28 16:19:57,115 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu bionic-security main restricted'
2021-01-28 16:19:57,115 DEBUG verifySourcesListEntry: deb http://security.ubuntu.com/ubuntu focal main restricted
2021-01-28 16:19:57,115 DEBUG url_downloadable: http://security.ubuntu.com/ubuntu/dists/focal/Release
2021-01-28 16:19:57,115 DEBUG s='http' n='security.ubuntu.com' p='/ubuntu/dists/focal/Release' q='' f=''
2021-01-28 16:19:57,134 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security main restricted' updated to new dist
2021-01-28 16:19:57,134 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu bionic-security universe'
2021-01-28 16:19:57,134 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security universe' updated to new dist
2021-01-28 16:19:57,134 DEBUG examining: 'deb http://security.ubuntu.com/ubuntu bionic-security multiverse'
2021-01-28 16:19:57,135 DEBUG entry 'deb http://security.ubuntu.com/ubuntu focal-security multiverse' updated to new dist
2021-01-28 16:19:57,138 DEBUG running doUpdate() (showErrors=True)
2021-01-28 16:20:11,116 DEBUG openCache()
2021-01-28 16:20:12,073 DEBUG Comparing 5.4.0-54 with
2021-01-28 16:20:12,074 DEBUG Comparing 5.4.0-58 with 5.4.0-54
2021-01-28 16:20:12,074 DEBUG Comparing 5.4.0-64 with 5.4.0-58
2021-01-28 16:20:12,332 DEBUG /openCache(), new cache size 67657
2021-01-28 16:20:12,332 DEBUG need_server_mode(): run in 'desktop' mode, (because of pkg 'ubuntu-desktop')
2021-01-28 16:20:12,333 DEBUG quirks: running PreDistUpgradeCache
2021-01-28 16:20:12,333 DEBUG running Quirks.PreDistUpgradeCache
2021-01-28 16:20:12,333 INFO checking for python-dbg
2021-01-28 16:20:12,333 INFO checking for python-doc
2021-01-28 16:20:12,333 INFO checking for python-minimal
2021-01-28 16:20:12,333 INFO installing python-is-python2 because python-minimal was installed
2021-01-28 16:20:12,333 DEBUG Installing 'python-is-python2' (python-minimal was installed on the system)
2021-01-28 16:23:12,303 ERROR Dist-upgrade failed: 'E:Unable to correct problems, you have held broken packages.'
2021-01-28 16:23:12,306 DEBUG abort called
2021-01-28 16:23:12,307 DEBUG openCache()
2021-01-28 16:23:15,917 DEBUG Comparing 5.4.0-54 with
2021-01-28 16:23:15,917 DEBUG Comparing 5.4.0-58 with 5.4.0-54
2021-01-28 16:23:15,917 DEBUG Comparing 5.4.0-64 with 5.4.0-58
2021-01-28 16:23:16,329 DEBUG /openCache(), new cache size 101660

and here is apt.log

Log time: 2021-01-28 16:19:45.851060
Log time: 2021-01-28 16:20:12.314792
  MarkInstall python-is-python2:amd64 < none -> 2.7.17-4 @un uN Ib > FU=1
  Installing python2 as Depends of python-is-python2
    MarkInstall python2:amd64 < none -> 2.7.17-2ubuntu4 @un uN Ib > FU=0
    Installing python2-minimal as PreDepends of python2
      MarkInstall python2-minimal:amd64 < none -> 2.7.17-2ubuntu4 @un uN Ib > FU=0
       Removing: python-minimal
        MarkDelete python-minimal:amd64 < 2.7.15~rc1-1 @ii mK > FU=0
    Installing libpython2-stdlib as Depends of python2
      MarkInstall libpython2-stdlib:amd64 < none -> 2.7.17-2ubuntu4 @un uN Ib > FU=0
       Removing: libpython-stdlib
        MarkDelete libpython-stdlib:amd64 < 2.7.15~rc1-1 @ii mK > FU=0
     Removing: python
      MarkDelete python:amd64 < 2.7.15~rc1-1 @ii mK Ib > FU=0
Starting pkgProblemResolver with broken count: 1
Starting 2 pkgProblemResolver with broken count: 1
Investigating (0) nodejs:amd64 < 14.15.4-1nodesource1 @ii mK Ib >
Broken nodejs:amd64 Depends on python-minimal:amd64 < 2.7.15~rc1-1 @ii gR >
  Considering python-minimal:amd64 1 as a solution to nodejs:amd64 82
  Added python-minimal:amd64 to the remove list
  Fixing nodejs:amd64 via keep of python-minimal:amd64
  MarkKeep python-minimal:amd64 < 2.7.15~rc1-1 @ii gR > FU=0
Investigating (0) python2-minimal:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib >
Broken python2-minimal:amd64 Breaks on python-minimal:amd64 < 2.7.15~rc1-1 @ii gK > (< 2.7.15-2)
  Considering python-minimal:amd64 1 as a solution to python2-minimal:amd64 1
  MarkKeep python2-minimal:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib > FU=0
  Holding Back python2-minimal:amd64 rather than change python-minimal:amd64
Investigating (1) python2:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib >
Broken python2:amd64 PreDepends on python2-minimal:amd64 < none | 2.7.17-2ubuntu4 @un umH > (= 2.7.17-2ubuntu4)
  Considering python2-minimal:amd64 1 as a solution to python2:amd64 1
  MarkKeep python2:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib > FU=0
  Holding Back python2:amd64 rather than change python2-minimal:amd64
Investigating (2) python-is-python2:amd64 < none -> 2.7.17-4 @un pumN Ib >
Broken python-is-python2:amd64 Depends on python2:amd64 < none | 2.7.17-2ubuntu4 @un umH >
  Considering python2:amd64 1 as a solution to python-is-python2:amd64 9999
  Re-Instated python2-minimal:amd64
  Re-Instated python2:amd64
Investigating (2) python2-minimal:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib >
Broken python2-minimal:amd64 Breaks on python-minimal:amd64 < 2.7.15~rc1-1 @ii gK > (< 2.7.15-2)
  Considering python-minimal:amd64 1 as a solution to python2-minimal:amd64 1
  MarkKeep python2-minimal:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib > FU=0
  Holding Back python2-minimal:amd64 rather than change python-minimal:amd64
Investigating (3) python2:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib >
Broken python2:amd64 PreDepends on python2-minimal:amd64 < none | 2.7.17-2ubuntu4 @un umH > (= 2.7.17-2ubuntu4)
  Considering python2-minimal:amd64 1 as a solution to python2:amd64 1
  MarkKeep python2:amd64 < none -> 2.7.17-2ubuntu4 @un umN Ib > FU=0
  Holding Back python2:amd64 rather than change python2-minimal:amd64
Investigating (4) python-is-python2:amd64 < none -> 2.7.17-4 @un pumN Ib >
Broken python-is-python2:amd64 Depends on python2:amd64 < none | 2.7.17-2ubuntu4 @un umH >
  Considering python2:amd64 1 as a solution to python-is-python2:amd64 9999
Done
Log time: 2021-01-28 16:23:16.315041

So I had python2 on this machine but it is choking the upgrade.

I do have python2 on this system:
$ python2 -V
Python 2.7.17

but it seems unremovable:
sudo apt remove python2 --simulate
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package python2

FIXED with 'autoremove'

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.42
ProcVersionSignature: Ubuntu 5.4.0-64.72~18.04.1-generic 5.4.78
Uname: Linux 5.4.0-64-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.21
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Thu Jan 28 16:22:47 2021
InstallationDate: Installed on 2020-03-18 (316 days ago)
InstallationMedia: Ubuntu 18.04.4 LTS "Bionic Beaver" - Release amd64 (20200203.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2021-01-28 (0 days ago)
VarLogDistupgradeTermlog:

[Brian Murray (brian-murray)]

Thanks for taking the time to report this upgrade failure. There is currently a new version of the release upgrader availalbe 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!