bloop run not killing processes when exited

[kubukoz]

This is a bit of a flaky / hard to reproduce issue (by nature), so I apologize upfront for the lack of a reliable reproduction.

Every now and then, after using a bloop (usually started by Metals for an sbt+bloop project) for some time, when I use bloop run <proj>, it will no longer kill processes it starts.

I always interrupt these bloop run calls with ctrl+c, and it does exit pretty much immediately, but on the rare occasion it'll keep the application running. Usually there's an HTTP server in the app, and the outcome showcases as "Address already in use" when I make another attempt to bloop run. This can also be detected with lsof -i :8080 (for example).

Worth noting: once this "happens once", I believe any further attempt to bloop run will not exit properly, i.e. this is something that persists until the server is killed itself - it's not random in that sense.

I just wanted to document this issue (and possibly find out if it's a duplicate), until I have a proper reproduction I don't expect it to be easily fixable.