Problem with »Scion« not found

When I try to use HaskellFP for Eclipse, I always get a popup that the Scion server failed to build. In the console appears the following message:

cabal: The program ghc version >开发者_如何转开发=6.4 is required but it could not be found.

I have the latetest Haskell platform installed. All programs (but not eclispe) are installed in ~/usr.

I am new to Eclipse. Can someone please help me?

Maybe you can find the instruction for scion on this page:

http://sourceforge.net/projects/eclipsefp/files/EclipseFP%202%20branch/2.0.4/

"Scion: EclipseFP relies on Scion, the Haskell IDE library, for a lot of its functionality. See http://code.google.com/p/scion-lib/ for more information."