Bug in GHC 6.2.1

This is the program:

import Control.Concurrent

main = do
  m <- newEmptyMVar
  forkIO $ do
    s <- getLine
    putMVar m s
  s <- takeMVar m
  putStrLn s

> ghc --make Bug.hs                          [21:54]
Chasing modules from: Bug.hs
Compiling Main             ( Bug.hs, Bug.o )
Linking ...
> ./a.out                                    [21:57]
# Now hit Ctrl-C
a.out: internal error: main thread has been GC'd
    Please report this as a bug to glasgow-haskell-bugs@xxxxxxxxxxx,
    or http://www.sourceforge.net/projects/ghc/

Ben