Hm, if you don't turn on GeneralizedNewtypeDeriving with GHC, shouldn't it fail earlier on the definition of the newtype that you are deriving things for?
Yea, it looks like it does honor -XForeignFunctionInterface. The "Monad.hs" below defines the newtypes, and haddock doesn't seem to have a problem with it.
You should not pass --haddock-options to haddock itself. It's used to tell Cabal which options to give to Haddock. So the right line would be:
haddock --optghc=-XGeneralizedNewtypeDeriving
Sorry, was a bad paste, i was running it through Cabal's Setup.hs. Heres the output from running haddock directly on the two files: ------------------ $ haddock.exe -v \ --optghc=-XGeneralizedNewtypeDeriving \ --optghc=-DCALLCONV=ccall \ --optghc=-XCPP --optghc=-XForeignFunctionInterface \ Graphics/Rendering/OGL/GL/FlushFinish.hs Graphics\Rendering\OGL\GL\FlushFinish.hs:39:0: Unacceptable result type in foreign declaration: GL () When checking declaration: foreign import ccall unsafe "static &glFlush" flush :: GL () Graphics\Rendering\OGL\GL\FlushFinish.hs:47:0: Unacceptable result type in foreign declaration: GL () When checking declaration: foreign import ccall unsafe "static &glFinish" finish :: GL () haddock: Failed to check module: Graphics.Rendering.OGL.GL.FlushFinish ------------------ $ haddock.exe -v \ --optghc=-XGeneralizedNewtypeDeriving --optghc=-DCALLCONV=ccall --optghc=-XCPP --optghc=-XForeignFunctionInterface Graphics/Rendering/OGL/Monad.hs Warning: main:Graphics.Rendering.OGL.Monad: could not find link destinations for: GHC.IOBase.IO Control.Arrow.Kleisli GHC.Base.Monad GHC.Base.Functor Control.Monad.Trans.MonadIO ### looks ok. -----------------