Resolving dependencies... cabal: Could not resolve dependencies: next goal: roguestar-engine (user goal) rejecting: roguestar-engine-0.6.0.1, roguestar-engine-0.6.0.0, roguestar-engine-0.4.0.3, roguestar-engine-0.4.0.2, roguestar-engine-0.4.0.1 (constraint from user target requires ==0.4.0.0) trying: roguestar-engine-0.4.0.0 trying: base-4.9.0.0/installed-4.9... (dependency of roguestar-engine-0.4.0.0) next goal: MaybeT (dependency of roguestar-engine-0.4.0.0) rejecting: MaybeT-0.1.2 (conflict: base==4.9.0.0/installed-4.9..., MaybeT => base<4.8) rejecting: MaybeT-0.1.1, MaybeT-0.1.0 (conflict: roguestar-engine => MaybeT>=0.1.2 && <0.2) Dependency tree exhaustively searched.