Resolving dependencies...
Downloading ref-0.1.1.1...
Configuring ref-0.1.1.1...
Building ref-0.1.1.1...
Preprocessing library ref-0.1.1.1...

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-0.1.1.1
cabal: Error: some packages failed to install:
ref-0.1.1.1 failed during the building phase. The exception was:
ExitFailure 1