Hi! I am working on a program that uses ghc as a library to typecheck code. I want to profile the program (compiling with '-prof -auto-all' and running with '+RTS -p'). Trying to compile, results in the following message: Could not find module `GHC': Perhaps you haven't installed the profiling libraries for package ghc-6.6.1? I built ghc-6.6.1 from source without changing any configuration files. The building guide (http://hackage.haskell.org/trac/ghc/wiki/Building/QuickStart) says, this would install the compiler WITH profiling libraries. As i understand it, this somehow excludes the ghc package. (Maybe because it is not widely used?) Is this understanding right? Is it possible (and if, how) to compile ghc with a profiling version of the ghc package? I tried to add GhcStage2HcOpts = -Rghc-timing -prof -auto-all GhcStage2LibHcOpts = -prof -auto-all to mk/build.mk, but i am getting the following build error in stage 2: ghc-6.6.1: combination not supported: Threaded/Profiling Do i need to disable thread support? How would i do that? A second idea that comes to my mind is this: The ghc package is hidden in the standard installation, so i unhided (unhid?) it via 'ghc-pkg expose ghc'. Maybe it just exposed the non-profiling version and kept the profiling version hidden? How would i expose both? Any help appreciated... Sönke