Resolving dependencies... Downloading AFSM-0.1.3.1... Configuring AFSM-0.1.3.1... Building AFSM-0.1.3.1... Preprocessing library AFSM-0.1.3.1... src/Control/AFSM/SMFunctor.hs:18:8: Could not find module ‘Data.Functor.Compose’ It is a member of the hidden package ‘transformers-0.4.2.0@trans_GZTjP9K5WFq01xC9BAGQpF’. Perhaps you need to add ‘transformers’ to the build-depends in your .cabal file. Use -v to see a list of the files searched for. Failed to install AFSM-0.1.3.1 cabal: Error: some packages failed to install: AFSM-0.1.3.1 failed during the building phase. The exception was: ExitFailure 1