Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: clafer (user goal)
rejecting: clafer-0.4.2.1, 0.4.2, 0.4.1, 0.4.0, 0.3.10, 0.3.9, 0.3.8, 0.3.7
(global constraint requires ==0.3.6.1)
trying: clafer-0.3.6.1
trying: base-4.8.1.0/installed-4f7... (dependency of clafer-0.3.6.1)
next goal: MaybeT (dependency of clafer-0.3.6.1)
rejecting: MaybeT-0.1.2 (conflict: base==4.8.1.0/installed-4f7..., MaybeT =>
base<4.8)
rejecting: MaybeT-0.1.1, 0.1.0 (conflict: clafer => MaybeT>=0.1.2)
Dependency tree exhaustively searched.