Resolving dependencies... cabal: Could not resolve dependencies: trying: DefendTheKing-0.3.1 (user goal) trying: base-4.8.1.0/installed-4f7... (dependency of DefendTheKing-0.3.1) next goal: MaybeT (dependency of DefendTheKing-0.3.1) rejecting: MaybeT-0.1.2, 0.1.1 (conflict: base==4.8.1.0/installed-4f7..., MaybeT => base<4.8) rejecting: MaybeT-0.1.0 (conflict: base==4.8.1.0/installed-4f7..., MaybeT => base<4.3) Dependency tree exhaustively searched.