> These steps seem to provoke a failure of the original test quite reliably on macOS:

> 1. add the call (sleep-for 1) both before and after (proced-refine), to widen the windows
> 2. in a different terminal, keep the command

>  while true; do /bin/sleep 2 & sleep 0.1; done

Thanks for this, with the help of these instructions I can reproduce.

> but I think the test should still pass in this case

Sorry I was wrong here, if the process used for the refinement exited between proced being called, and then `(proced-update t)` being called, then the whole process list will be shown as proced would skip applying the refinement.  So I think using (proced-update) instead of (proced-update t) is the simplest fix since it means `proced-process-alist` will never be refreshed.  I've re-attached the patch from before, but with a bit more explanation.