Using The Darcs version of HList (http://darcs.haskell.org/HList/), I can do simple things with (H)lists just fine, so --angus = Key 42 -- .*. Name "Angus" -- .*. Cow -- .*. Price 75.5 -- .*. HNil --main = putStrLn (show angus) works, On the other hand examples from the HList paper for extensible records like --key = firstLabel FootNMouth "key" --name = nextLabel key "name" --breed = nextLabel name "breed" --price = nextLabel breed "price" do not compile with errors --Main.hs:15:8-17: Not in scope: `firstLabel' --Main.hs:16:8-16: Not in scope: `nextLabel' A quick show "ghc-pkg describe HList" shows that --exposed-modules: HList --hidden-modules: Label4 CommonMain Variant GhcSyntax GhcRecord -- Record HZip TIC TIP HTypeIndexed HOccurs HArray GhcExperiments -- HListPrelude TypeEqBoolGeneric TypeEqGeneric1 TypeCastGeneric1 -- FakePrelude So the question is do I need to play around with the cabal file to expose the right stuff? Or has the syntax changed? I get errors running "./setup haddock" (configure, build, install, are fine). Are the HList api docs available anywhere online? Rahul