Marcin 'Qrczak' Kowalczyk wrote: [snip]

...

Since the very purpose of killThread is to kill the damn thread, I find it inconvenient to have to wrap any thread which is supposed to be killable with Exception.catch to avoid the message. Worse: it should use block and unblock, otherwise there is a small window where killing the thread will still display the message. [snip] I agree with this. I also find it mildly irritating having to catch exceptions to stop GHC informing me that it's just garbage

collected a thread which is permanently deadlocked.

Ok, so which exceptions should be displayed? - Marcin says all async exceptions should be suppressed in child threads. - George says BlockedOnDeadMVar messages should also be suppressed (presumably only on child threads). any others? I'm not sure I agree that StackOverflow/HeapOverflow messages should be suppressed. It might be really confusing if your program just deadlocks instead of completing, when what actually happened was one of the child threads got a stack overflow and died silently. I can see the point about ThreadKilled though. There's only one way to kill a thread, and that's with killThread, so you don't want to see a message saying the thread was killed (except that the presence of the message indicates that the thread was alive before it was killed ;-). Cheers, Simon