Dear Group, Today I tried to compile snap 0.6 with ghc 7.2, (using virthualenv, which is GREAT by the way) and got the following error somewhere along the way got a message about aeson-native requires deepseq-1.1.0.2 but I had deepseq-1.2.0.1 installed. So I unpacked aeson-native-0.3.3.1 in my virthualenv and changed the build-depends to just deepseq which caused: Configuring aeson-native-0.3.3.1... Preprocessing library aeson-native-0.3.3.1... Building aeson-native-0.3.3.1... [2 of 6] Compiling Data.Aeson.Types ( Data/Aeson/Types.hs, dist/build/Data/Aeson/Types.o ) Data/Aeson/Types.hs:196:22: No instance for (NFData Object) arising from a use of `rnf' Possible fix: add an instance declaration for (NFData Object) In the expression: rnf o In an equation for `rnf': rnf (Object o) = rnf o In the instance declaration for `NFData Value' cabal: Error: some packages failed to install: aeson-native-0.3.3.1 failed during the building phase. The exception was: ExitFailure 1 A little investigating and I discovered that instance (NFData k, NFData a) => NFData (Data.Map.Map k a) where rnf = rnf . Data.Map.toList is in deepseq-1.1.0.2 but not in deepseq-1.2.0.1. Adding it back got aeson-native-0.3.3.1 and later snap-0.6 to compile just fine. So I guess my question is: Is there a reason that the map instance was removed from deepseq-1.2.0.1, and can we please put it back in? Thanks. Best wishes, Henry Laxen