… and instead only the Ubuntu version (LTS?) will install. It took me a little while to troubleshoot so I write this here to save time for anyone else struggling with this.
This is because the ESM respositories are higher priority. To resolve this you can edit /etc/apt/preferences.d/ubuntu-pro-esm-apps and set the priority to less than 500 and then run sudo apt update and sudo apt upgrade again. This should upgrade the installed Ubuntu version with the Zabbly version plus a bunch of new dependencies.
Yep, I used apt cache and policy to try to figure out what was going on. But what you get is a list of the available Zabbly packages (which are newer versions, but not marked as candidates) and the Ubuntu ones, which have no upgrade candidates beyond 6.0, and no explanation why. It took me quite a lot more research to resolve the situation.
It would be relatively easy for apt to tell you it’s picking a particular stream because the ESM repositories are highest priority in the system, eg “the following newer versions are available on other repositories but are not eligible because the current repository is a highest priority.” If it does say that anywhere I didn’t see it.
As a second order problem, if you blindly apt remove the Ubuntu Incus LTS it removes a large amount of packages and dependencies which would leave you in quite a mess.
If I were to explain the issue, I would get the output of apt policy (relevant sections) and apt policy incus before the fix, and after the fix. I would show the output and help explain the differences.
This is the second report of the problem, and likely more will join here for this.