Templates restored from backup created in older release silently continue to target old repos even after updating #8701
Description
The problem you're addressing (if any)
Users who install 4.2 via a clean install may not notice they need to upgrade the Qubes template sources to 4.2. Failing to do that they may miss on critical integrations for 4.2 like VMExec (for the updater to work) and most importantly, after 4.1 is EOL, it'll simply stop getting Qubes packages updates. Worse: from the user perspective the update process will not return any errors since there are no new packages.
The solution you'd like
Minimal solution: inform the user
At the very least warn in the updater that the templates are imported from Qubes 4.1 and need to have their sources upgraded.
As for the overall issue, in 4.2 templates started advertised for which qubes version they are (more or less based on the version of qubes-core-agent package). This information isn't used anywhere yet - I guess we should add some warning based on that.
-- Marek (source)
Better solution: upgrade it for them
Do the template repo upgrades for the user through the updater tool.