[Haskell-cafe] Unexpected results from ExitCode

I have a program (test.hs):

module Main (main) where import System.Exit main :: IO ExitCode main = do return (ExitFailure 1)

In another program, I invoke it via 'system':

exitCode <- system ".\\test.exe" case (exitCode) of ExitFailure failCnt -> do putStrLn $ "-- Fail count is: " ++ show failCnt exitFailure ExitSuccess -> do putStrLn $ "-- OK." exitSuccess

but it always gets ExitSuccess (not ExitFailure failCnt as I expected). (I am running under Windows.) My other use of system (such as with ghc commands) works okay, sometimes getting success, sometimes failure, as expected. Any suggestions much appreciated. Thanks, -- Peter