Resolving dependencies... cabal: Could not resolve dependencies: next goal: helm (user goal) rejecting: helm-0.7.1, 0.7.0, 0.6.1 (global constraint requires ==0.6.0) trying: helm-0.6.0 trying: base-4.8.1.0/installed-4f7... (dependency of helm-0.6.0) trying: transformers-0.4.2.0/installed-21d... (dependency of helm-0.6.0) next goal: mtl (dependency of helm-0.6.0) rejecting: mtl-2.2.1, 2.2.0.1, 2.2 (conflict: helm => mtl>=2.1 && <2.2) rejecting: mtl-2.1.3.1, 2.1.2 (conflict: transformers==0.4.2.0/installed-21d..., mtl => transformers==0.3.*) rejecting: mtl-2.1.1, 2.1 (conflict: base==4.8.1.0/installed-4f7..., mtl => base<4.6) rejecting: mtl-2.0.1.1, 2.0.1.0, 2.0.0.0, 1.1.1.1, 1.1.1.0, 1.1.0.2, 1.1.0.1, 1.1.0.0, 1.0 (conflict: helm => mtl>=2.1 && <2.2) Dependency tree exhaustively searched.