[Haskell-cafe] deepseq-184.108.40.206 missing Data.Map instance
nadine.and.henry at pobox.com
Tue Nov 15 23:26:04 CET 2011
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-220.127.116.11 but I had deepseq-18.104.22.168 installed. So I
unpacked aeson-native-0.3.3.1 in my virthualenv and changed the
build-depends to just deepseq which caused:
Preprocessing library aeson-native-0.3.3.1...
[2 of 6] Compiling Data.Aeson.Types ( Data/Aeson/Types.hs,
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:
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-22.214.171.124 but not in deepseq-126.96.36.199. 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-188.8.131.52, and can we please put it back in?
More information about the Haskell-Cafe