George Russell wrote:

For the development snapshot 6.3.20031201, System.Posix.forkProcess has the type IO () -> IO System.Posix.Types.ProcessID. In 6.0.1 it has type IO () -> IO (Maybe System.Posix.Types.ProcessID). Is this change intentional, and if so how are you supposed to test after the fork if this is the parent or child process?

The following example should explain everything: Old Version: do mbPid <- forkProcess case mbPid of Nothing -> putStrLn "Child" Just pid -> putStrLn $ "Parent of " ++ show pid New Version: do pid <- forkProcess (putStrLn "Child") putStrLn $ "Parent of " ++ show pid Cheers, Wolfgang