Resolving dependencies...
Downloading Ref-0.1.1.0...
Configuring Ref-0.1.1.0...
Building Ref-0.1.1.0...
Preprocessing library Ref-0.1.1.0...

src/Data/Ref.hs:12:8:
    Could not find module `Data.Ref.CAS'
    Use -v to see a list of the files searched for.
Failed to install Ref-0.1.1.0
cabal: Error: some packages failed to install:
Ref-0.1.1.0 failed during the building phase. The exception was:
ExitFailure 1