* On Sunday, December 27 2009, Viktor Deryagin wrote:

On Sun, Dec 27, 2009 at 12:56 AM, Ferenc Wagner wrote: ...

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What is your unix package version?

What is "unix package"? Sorry for stupid question :)

$ ghc-pkg list unix I'm not sure how to help with the rest of this troubleshooting, however. -- Adam

On Sun, Dec 27, 2009 at 01:25:40AM +0100, Ferenc Wagner wrote:

Adam Vogt writes:

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* On Sunday, December 27 2009, Viktor Deryagin wrote:

...

On Sun, Dec 27, 2009 at 12:56 AM, Ferenc Wagner wrote: ...

...

What is your unix package version?

What is "unix package"? Sorry for stupid question :)

$ ghc-pkg list unix

I'm not sure how to help with the rest of this troubleshooting, however.

Nevermind, I've found the bug. spawnPipe changed from forkProcess to xfork. xfork contains createSession, but spawnPipe also kept its own, so there're two in the code path now. The latter should be removed.

Thanks for tracking this down, it was my mistake when adding xfork. I've pushed a patch that fixes the issue. Cheers, Spencer Janssen

On Sat, Dec 26, 2009 at 06:41:59PM -0600, Spencer Janssen wrote:

On Sun, Dec 27, 2009 at 01:25:40AM +0100, Ferenc Wagner wrote:

...

Adam Vogt writes:

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* On Sunday, December 27 2009, Viktor Deryagin wrote:

...

On Sun, Dec 27, 2009 at 12:56 AM, Ferenc Wagner wrote: ...

...

What is your unix package version?

What is "unix package"? Sorry for stupid question :)

$ ghc-pkg list unix

I'm not sure how to help with the rest of this troubleshooting, however.

Nevermind, I've found the bug. spawnPipe changed from forkProcess to xfork. xfork contains createSession, but spawnPipe also kept its own, so there're two in the code path now. The latter should be removed.

Thanks for tracking this down, it was my mistake when adding xfork. I've pushed a patch that fixes the issue.

Have you actually pushed this yet? I don't get any patches when doing a darcs pull. -Brent

Viktor Deryagin writes:

On Sun, Dec 27, 2009 at 12:56 AM, Ferenc Wagner wrote:

...

Very strange, all the setsid() syscalls are doubled like for example

[pid 11584] setsid()                    = 11584 [pid 11584] setsid()                    = -1 EPERM (Operation not permitted) [pid 11584] write(2, "xmonad-i386-linux: ", 19) = 19 [pid 11584] write(2, "createSession: permission denied"..., 58) = 58 [pid 11584] write(2, "\n", 1)           = 1

Xmonad should run four instances of dzen2 (4 spawnPipe entries in xmonad.hs), maybe this is the reason?

There are four such pairs of setsid calls in your strace output, corresponding to the four spawnPipes, but I don't understand why they are *pairs*, like above...

$ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.10.4

Same as mine.

...

What is your unix package version?

What is "unix package"? Sorry for stupid question :)

Here's the way to find out: $ ghc-pkg describe unix | grep version version: 2.3.2.0

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Please compile the following test program, run it under strace -f and send the output back:

Attached.

Thanks, this contains a simple setsid() call, as it should. Please test another short program the same way:

import XMonad.Util.Run main = spawnPipe "cat" -- Thanks, Feri.