tried to upgrade a machine from 18.04 to 20.04

[donwood]

Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

This was caused by:
* Upgrading to a pre-release version of Ubuntu
This is most likely a transient problem,
please try again later.
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 looked at the suggested logs and my skill level was not up to the challenge.

I did the 'ubuntu-bug ubuntu-release-upgrader-core' and it brought be to this page, so I hope that info is attached.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.37
ProcVersionSignature: Ubuntu 4.15.0-99.100-generic 4.15.18
Uname: Linux 4.15.0-99-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.14
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: MATE
Date: Wed May 6 13:44:55 2020
InstallationDate: Installed on 2018-07-21 (655 days ago)
InstallationMedia: Ubuntu-MATE 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2020-05-06 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Brian Murray (brian-murray)]

We recently updated the release upgrader and it should include a fix for the failure you encountered. Could you please try the upgrade process again? Thanks in advance.

[donwood (donwood)]

Thanks Brian,

I re-ran the upgrade and I did not encounter the error. I believe the
latest release of the updater has fixed the issue. If I am the one
holding the ticket open then please close it.

Thanks to you and the whole security team for all your hard work keeping
us safe.

Cheers!

On 7/30/20 1:29 PM, Brian Murray wrote:
> We recently updated the release upgrader and it should include a fix for
> the failure you encountered. Could you please try the upgrade process
> again? Thanks in advance.
>
> ** Changed in: ubuntu-release-upgrader (Ubuntu)
> Status: Confirmed => Incomplete
>