I've had my own problems while developing a successor version of the syb package. For starters, cabal fails to install the package:
>cabal install
Resolving dependencies...
cabal: dependencies conflict: base-3.0.3.0 requires syb ==0.1.0.0 however
syb-0.1.0.0 was excluded because syb-0.2.0.0 was selected instead
syb-0.1.0.0 was excluded because of the top level dependency syb ==0.2.0.0
Note that this package explicitly requires base >= 4.0. Anyway,
runghc Setup.hs install does it, though. However, after having it installed I can't use it, getting this when any module imports Data.Generics:
Bad interface file: C:\Program Files (x86)\Haskell\syb-0.2.0.0\ghc-6.10.1\Data\Generics.hi
Something is amiss; requested module syb:Data.Generics differs from name found in the interface file syb-0.2.0.0:Data.Generics
Failed, modules loaded: none.
I talked about this on IRC before and remember this might have had something to do with syb having been unversioned in the release of GHC 6.10.1. But I hope someone can clarify this better...
Cheers,
Pedro