Resolving dependencies...
Downloading HRay-1.2.3...
Configuring HRay-1.2.3...
Building HRay-1.2.3...
Preprocessing executable 'HRay' for HRay-1.2.3...

HRayMain.lhs:1:1:
    Ambiguous module name `Prelude':
      it was found in multiple packages: base haskell98-2.0.0.2
Failed to install HRay-1.2.3
cabal: Error: some packages failed to install:
HRay-1.2.3 failed during the building phase. The exception was:
ExitFailure 1