Hi, I am trying to make happstack work in my box, which is using ghc 7. While compiling HStringTemplate, which I did a little modification to make it work, I found that it does not work with template-haskell-2.5.0.0. I changed it to use template-haskell-2.4.0.1. This step worked fine. Then I got another error: $ cabal install Resolving dependencies... Configuring syb-with-class-0.6.1.1... Preprocessing library syb-with-class-0.6.1.1... Building syb-with-class-0.6.1.1... [1 of 4] Compiling Data.Generics.SYB.WithClass.Context ( Data/Generics/SYB/WithClass/Context.hs, dist/build/Data/Generics/SYB/WithClass/Context.o ) [2 of 4] Compiling Data.Generics.SYB.WithClass.Basics ( Data/Generics/SYB/WithClass/Basics.hs, dist/build/Data/Generics/SYB/WithClass/Basics.o ) [3 of 4] Compiling Data.Generics.SYB.WithClass.Derive ( Data/Generics/SYB/WithClass/Derive.hs, dist/build/Data/Generics/SYB/WithClass/Derive.o ) Data/Generics/SYB/WithClass/Derive.hs:23:1: Bad interface file: /home/magicloud/.cabal/lib/template-haskell-2.4.0.1/ghc-7.0.1/Language/Haskell/TH.hi Something is amiss; requested module template-haskell-2.4.0.1:Language.Haskell.TH differs from name found in the interface file template-haskell:Language.Haskell.TH cabal: Error: some packages failed to install: HStringTemplate-0.6.3 depends on syb-with-class-0.6.1.1 which failed to install. syb-with-class-0.6.1.1 failed during the building phase. The exception was: ExitFailure 1 How to resolve this? -- 竹密岂妨流水过 山高哪阻野云飞