Resolving dependencies... cabal: Could not resolve dependencies: trying: base-4.9.0.0/installed-4.9... (dependency of haskell-packages-0.2) trying: transformers-0.5.2.0/installed-0.5... (dependency of tagged-0.8.5:+transformers) trying: EitherT-0.2.0 (dependency of haskell-packages-0.2) next goal: monad-control (dependency of EitherT-0.2.0) rejecting: monad-control-1.0.1.0, monad-control-1.0.0.5, monad-control-1.0.0.4, monad-control-1.0.0.3, monad-control-1.0.0.2, monad-control-1.0.0.1, monad-control-1.0.0.0 (conflict: EitherT => monad-control>=0.3 && <0.4) rejecting: monad-control-0.3.3.1, monad-control-0.3.3.0 (conflict: transformers==0.5.2.0/installed-0.5..., monad-control => transformers>=0.2 && <0.5) rejecting: monad-control-0.3.2.3, monad-control-0.3.2.2, monad-control-0.3.2.1 (conflict: transformers==0.5.2.0/installed-0.5..., monad-control => transformers>=0.2 && <0.4) rejecting: monad-control-0.3.2, monad-control-0.3.1.4 (conflict: base==4.9.0.0/installed-4.9..., monad-control => base>=3 && <4.7) rejecting: monad-control-0.3.1.3, monad-control-0.3.1.2, monad-control-0.3.1.1, monad-control-0.3.1 (conflict: base==4.9.0.0/installed-4.9..., monad-control => base>=3 && <4.6) rejecting: monad-control-0.3.0.1, monad-control-0.3 (conflict: base==4.9.0.0/installed-4.9..., monad-control => base>=3 && <4.5) rejecting: monad-control-0.2.0.3, monad-control-0.2.0.2, monad-control-0.2.0.1, monad-control-0.2, monad-control-0.1 (conflict: EitherT => monad-control>=0.3 && <0.4) Dependency tree exhaustively searched.