Comment 2 for bug 1733469

There's a bug in https://github.com/juju/juju/blob/develop/worker/metrics/spool/listener.go#L76, which says "NewPeriodicWorker returns a periodic worker, that will call a stop function when it is killed."

That is only true if the worker is explicitly killed from the outside, and not if the worker dies due to an error from the inside. In the latter case, the stop function (which closes the Unix socket) is not called.