Could not calculate the upgrade

[Hangyeol Jeon]

Tried to upgrade Ubuntu 20.04 to 22.04, and got this error:

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'.

I tried to unselect everything in Software & Updates - Other Software tab, and that did not help me.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.40
ProcVersionSignature: Ubuntu 5.4.0-144.161-generic 5.4.229
Uname: Linux 5.4.0-144-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.25
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Wed Mar 8 11:06:30 2023
InstallationDate: Installed on 2023-02-27 (8 days ago)
InstallationMedia: Ubuntu 18.04.6 LTS "Bionic Beaver" - Release amd64 (20210915)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to focal on 2023-03-08 (0 days ago)
VarLogDistupgradeTermlog:

[Nick Rosbrook (enr0n)]

Reviewing the files from your upgrade attempt, you have installed packages from the deadsnakes PPA. Some of the packages installed are newer than those in the official archive, which is keeping some python packages installed which then prevents the upgrade from being calculated. Please try using the ppa-purge tool to remove packages installed from ppa:deadsnakes/ppa. After that you can try upgrading again and if it still fails open a new bug report. Thanks and good luck!