Non terminating thunk resolution blocks world, even in the case of forkOS

[timthelion]

Please see:  http://comments.gmane.org/gmane.comp.lang.haskell.cafe/102479

{-# LANGUAGE ScopedTypeVariables? #-} import Control.Concurrent

main = do putStrLn "Hello" forkOS neverEnds putStrLn "Bye bye" --We never get here(or at least I don't).

neverEnds = do let (a::String) = a putStrLn a

[timthelion]

Properly formated version of post.

[cdupont]

I reproduced the bug in 7.4.1 compiled with ghc -threaded. However, runnning "main" in ghci doesn't show the bug (it finishes correctly).

[Yuras]

Seems to be a duplicate of #367: you have a loop without allocations and the scheduler doesn't have chance to reschedule the thread.

I can reproduce it with the HEAD with "-O0". With "-O1" it works ok for me. It works with "-O0 -fno-omit-yields" too.

[igloo]

Agreed, duplicate of #367.