Hello all,
I mentioned this problem before on IRC and remember this might have had something to do with syb having been unversioned in the release of GHC 6.10.1. However, I've tested this under 6.10.2-rc1 and the problem is still there. Concretely, the problem is: I've developed a sucessor package to syb-0.1.0.0. I can install it with runghc Setup.hs install. However, after having installed it I can't use it, getting this error when loading any module that imports Data.Generics: