Resolving dependencies...
Downloading egison-1.0.4...
Configuring egison-1.0.4...
Building egison-1.0.4...
Preprocessing executable 'egison' for egison-1.0.4...

Egison.hs:1:1:
    Ambiguous module name `Prelude':
      it was found in multiple packages: base haskell98-2.0.0.2
Failed to install egison-1.0.4
cabal: Error: some packages failed to install:
egison-1.0.4 failed during the building phase. The exception was:
ExitFailure 1