Odd behavior of ncurses with -threaded

[Simon Hengel]

Hello,
the following program should wait 3 seconds for user input before.  If
now user input occurs within that time, it just prints -1.

    {-# LANGUAGE ForeignFunctionInterface #-}
    module Main where

    import Foreign
    import Foreign.C.String
    import Foreign.C.Types
    import Foreign.C.Error

    foreign import ccall unsafe initscr :: IO (Ptr ())
    foreign import ccall unsafe endwin  :: IO CInt
    foreign import ccall unsafe getch   :: IO CInt
    foreign import ccall unsafe timeout :: CInt -> IO ()

    main = do
      initscr
      timeout 3000
      c <- getch
      endwin
      print c

This works just fine if I do not use the threaded RTS, say:

    ghc --make -lcurses Main.hs

However, with

    ghc --make -threaded -lcurses Main.hs

it prints -1 immediately without awaiting the 3 seconds.

Is that considered a bug? Should I open a ticket?

ghc:     6.12.1
linux:   2.6.32
ncurses: 5.7

Cheers,
Simon