All right. 
After a re-installation I could load my GTK2HS example successfully. 
But I received another error. What is the meaning of that?

A wrong architecture? 

Prelude> :l guitest.hs 
[1 of 1] Compiling Main             ( guitest.hs, interpreted )
Ok, modules loaded: Main.
*Main> main
Loading package transformers-0.2.2.0 ... linking ... done.
Loading package mtl-2.0.1.0 ... linking ... done.
Loading package array-0.3.0.2 ... linking ... done.
Loading package containers-0.4.0.0 ... linking ... done.
Loading package bytestring-0.9.1.10 ... linking ... done.
Loading package cairo-0.12.3.1 ... linking ... done.
Loading package glib-0.12.3.1 ... can't load .so/.DLL for: intl (dlopen(/usr/local/Cellar/gettext/0.18.1.1/lib/libintl.dylib, 9): no suitable image found.  Did find:
/usr/local/Cellar/gettext/0.18.1.1/lib/libintl.dylib: mach-o, but wrong architecture)
*Main> 





This is the Content of guitest.hs

import Graphics.UI.Gtk
main :: IO ()
main = do
  initGUI
  window <- windowNew
  button <- buttonNew
  set window [ containerBorderWidth := 10,
               containerChild := button ]
  set button [ buttonLabel := "Hello World" ]
  onClicked button (putStrLn "Hello World")
  onDestroy window mainQuit
  widgetShowAll window
  mainGUI


Thank you for any help !


Am 07.06.2012 um 09:40 schrieb Ivan Lazar Miljenovic:

On 7 June 2012 18:09, Tanja Piechnick <tanja.piechnick@stud.uni-due.de> wrote:
Thank you for your response.

If I execute "ghc-pkg list gtk" I receive this output:

ghc-pkg list gtk
/usr/local/Cellar/ghc/7.0.4/lib/ghc-7.0.4/package.conf.d
/Users/tanjapiechnick/.ghc/i386-darwin-7.0.4/package.conf.d

This means that you in fact _don't_ have the Haskell gtk package
installed (in the sense that GHC knows about it), which is why you
can't use it.


But "ghc-pkg check" gives me no results

No, this in fact is good: it means that you don't have a problem with
your Haskell libraries.


 if you have only very recently built gtk etc via mac homebrew, you need to
build the head version of gtk2hs and family


Ok, and where can I get these informations?

I'm not too sure about this; Carter can hopefully tell you more about
this (specifically which packages need to be built from HEAD, etc.).
But you're going to want to use the darcs repository at
http://code.haskell.org/gtk2hs/ .

--
Ivan Lazar Miljenovic
Ivan.Miljenovic@gmail.com
http://IvanMiljenovic.wordpress.com