Resolving dependencies...
cabal: Could not resolve dependencies:
trying: helm-0.7.1 (user goal)
trying: base-4.8.1.0/installed-4f7... (dependency of helm-0.7.1)
trying: transformers-0.4.2.0/installed-21d... (dependency of helm-0.7.1)
next goal: mtl (dependency of helm-0.7.1)
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.