On Mon, Dec 13, 2010 at 12:07:25AM +0200, Alex wrote: > Hi all. > > I am trying to install the "yi" editor using cabal-install, which in turns > installs the package 'derive-2.3.0.2'. I get the following error during > derive's compilation: > > [53 of 58] Compiling Data.Derive.Internal.Traversal ( > Data/Derive/Internal/Traversal.hs, > dist/build/Data/Derive/Internal/Traversal.o ) > > Data/Derive/Internal/Traversal.hs:34:0: > Illegal instance declaration for `Applicative (Writer w)' > (All instance types must be of the form (T t1 ... tn) > where T is not a synonym. > Use -XTypeSynonymInstances if you want to disable this.) > In the instance declaration for `Applicative (Writer w)' > cabal: Error: some packages failed to install: > derive-2.3.0.2 failed during the building phase. The exception was: > ExitFailure 1
The problem appears to be that derive-2.3.0.2 does not work with mtl-2. The newest version of derive does, but yi specifies a dependency on derive-2.3.*. One thing worth trying is to cabal fetch yi cd yi-0.6.2.4 $EDITOR yi.cabal and change the build-depends: derive >=2.3 && <2.4 line to build-depends: derive >=2.3 && <2.5 Then run 'cabal install' to build yi from the local directory. If it works, you should inform the yi maintaner. -Brent _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
