Interestingly I see a form of #2 in the Clojure community whenever a newer Clojurist asks if a stable library is still maintained. The answer is usually yes, but it hasn't needed an update for a while. Sometimes even I have to double check.
I’m thinking that a stable library should do a x.x.X release periodically that might go no further than bumping the version number (and maybe fixing typos in the docs) to make it clear it’s not abandoned.
cronjob
What if the library has been abandoned, but it's cronjob is still perpetually running somewhere on a free cloud server plan? Or even there will appear a cool SaaS which will auto-bump version number every X days with a free plan for open-source GitHub repos?
I'd prefer this to be solved in culture, not in code. New isn't always better; we need a better proxy for value than "amount of new stuff".
A counter that count the number of projects that use the library could be useful too. If 20000 projects use it, 300 more since last month. It's clearly alive even if there is no new feature/bug fix since a year.