Resolving dependencies... cabal: Could not resolve dependencies: next goal: HSmarty (user goal) rejecting: HSmarty-0.2.0.3 (constraint from user target requires ==0.2.0.2) trying: HSmarty-0.2.0.2 trying: base-4.9.0.0/installed-4.9... (dependency of HSmarty-0.2.0.2) trying: transformers-0.5.2.0/installed-0.5... (dependency of monad-control-1.0.1.0) next goal: mtl (dependency of HSmarty-0.2.0.2) rejecting: mtl-2.2.1, mtl-2.2.0.1, mtl-2.2 (conflict: HSmarty => mtl==2.1.*) rejecting: mtl-2.1.3.1, mtl-2.1.2 (conflict: transformers==0.5.2.0/installed-0.5..., mtl => transformers==0.3.*) rejecting: mtl-2.1.1, mtl-2.1 (conflict: base==4.9.0.0/installed-4.9..., mtl => base<4.6) rejecting: mtl-2.0.1.1, mtl-2.0.1.0, mtl-2.0.0.0, mtl-1.1.1.1, mtl-1.1.1.0, mtl-1.1.0.2, mtl-1.1.0.1, mtl-1.1.0.0, mtl-1.0 (conflict: HSmarty => mtl==2.1.*) Dependency tree exhaustively searched.