I'm trying to upgrade from 18.04 to 20.04, but toward the end of the "Setting new software channels" stage I received the following error message.
Could not calculate the upgrade
An unresolvable problem occurred while
calculating the upgrade.
This was likely caused by:
* Unofficial software packages not provided by Ubuntu
Please use the tool 'ppa-purge' from the ppa-purge
package to remove software from a
Launchpad PPA and try the upgrade again.
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've already looked at the most relevant post I could find, here. Following their guidance, as well as the instruction from the error, I looked at both main.log, to find where the process failed and at apt.log (with grep Broken). As far as the main.log goes, the relevant broken packages I saw were colord and ubuntu-desktop, which, as far as I could tell are ubuntu packages—and so, therefore probably not the problem?? As for apt.log, I'm seeing dozens of broken packages (if you can make heads or tails of the long list, they're here.
From what I understand, I need to remove broken non-ubuntu packages in order to proceed with the upgrade by this route. Is that right? If so, do I just have to look up each broken package to figure out how it got installed? That seems like a ton of work, is there some shortcut? Or is there some other way I could upgrade without sorting this out, without just going for a clean upgrade?
Thanks!
