When community members comment on long-closed issues, there's a number of
failure modes that make for a bad experience for them:
* Their comments are often missed entirely because notification settings make it
impractical for most developers to read comments on inactive issues.
* In our experience, the problem is only rarely a regression; because failures
are complex, totally different code paths can result in symptoms that initially
appear to be the same but turn out to be completely different under close
examination. This is particularly the case for issues fixed in very old
versions (sometimes 2 or more years old).
The Terraform core team uses a bot that locks issues after only 30 days. But
because we typically close issues automatically on PR merge but don't have
rolling releases, it'd frequently happen that unrelease fixes will have locked
comments, which isn't a good experience either. I've looked through the pace of
releases since Nomad 0.9.0 and the longest window between releases was 3
months. Set the window for the lock bot to 120 days to give us plenty of
breathing room so it doesn't feel like we're shutting down discussion
prematurely.