i tried to install wxGeneric and need syb-with-class. i got the package from hackage. configure runs fine, but when i build i get: Data/Generics/SYB/WithClass/Instances.hs:11:7: Could not find module `Data.Array': it is a member of package array-0.1.0.0, which is hidden but array-0.1.0.0 is installed, as shown later. what can be wrong? why is an installed package complained about as hidden? thanks for help! andrew frank@bernH:~/haskellSources/packages/syb-with-class-0.3$ ghc-pkg describe array name: array version: 0.1.0.0 license: BSD3 copyright: maintainer: libraries@haskell.org stability: homepage: package-url: description: This package defines the classes @IArray@ of immutable arrays and @MArray@ of arrays mutable within appropriate monads, as well as some instances of these classes. category: author: exposed: True exposed-modules: Data.Array Data.Array.Base Data.Array.Diff Data.Array.IArray Data.Array.IO Data.Array.MArray Data.Array.ST Data.Array.Storable Data.Array.Unboxed hidden-modules: Data.Array.IO.Internals import-dirs: /usr/lib/ghc-6.8.2/lib/array-0.1.0.0 library-dirs: /usr/lib/ghc-6.8.2/lib/array-0.1.0.0 hs-libraries: HSarray-0.1.0.0 extra-libraries: extra-ghci-libraries: include-dirs: includes: depends: base-3.0.1.0 hugs-options: cc-options: ld-options: framework-dirs: frameworks: haddock-interfaces: /usr/share/doc/ghc6-doc/libraries/array/array.haddock haddock-html: /usr/share/doc/ghc6-doc/libraries/array f