runInteractiveProcess is broken

[Simon Marlow]

I can't repeat this, it works here:

*Main> test1
ExitSuccess
*Main> test2
Just ExitSuccess

(after changing /usr/bin/sleep to /bin/sleep).

The only thing I can think of is that you somehow have a SIGCHLD handler
that calls wait(), but I don't see where that can be happening.  GHC
doesn't have any other mechanism for calling wait(), so I don't
understand how the zombies are disappearing before waitForProcess is
called.

Maybe run it through strace and send us the output?

Cheers,
	Simon

On 26 October 2004 19:00, Peter Simons wrote:

> Neither of these functions returns the return code of the
> external process as promised:
> 
>   import System.IO hiding ( catch, try )
>   import System.Process
>   import Control.Concurrent
> 
>   sleep :: Int -> IO ()
>   sleep n = threadDelay (abs(n) * 1000000)
> 
>   test1 :: IO ()
>   test1 = do
>     (_,_,_, pid) <- runInteractiveProcess "/usr/bin/sleep" ["1"]
>     Nothing Nothing sleep 5
>     rc <- waitForProcess pid
>     print rc
> 
>   -- *Main> test1
>   -- *** Exception: waitForProcess: does not exist (No child
> processes) 
> 
>   test2 :: IO ()
>   test2 = do
>     (_,_,_, pid) <- runInteractiveProcess "/usr/bin/sleep" ["1"]
>     Nothing Nothing sleep 5
>     rc <- getProcessExitCode pid
>     print rc
> 
>   -- *Main> test2
>   -- Nothing
> 
> I'm using the ghc from CVS-HEAD on Linux/x86.
> 
> Peter
> 
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