I'm trying to upgrade from 18.10 to 19.10, using
sudo do-release-upgrade however I only get an error:
An upgrade from 'cosmic' to 'eoan' is not supported with this tool.
I performed the steps to update my
sources.list to point to old-release server, as suggested here: How to install software or upgrade from an old unsupported release?
This did not help. I get the same error.
It's still possible to do the upgrade, you just have to hack some files per this blog post in order to upgrade to 19.04 first. I was able to upgrade successfully following his method.
Quoting the blog: