Resolving dependencies... cabal: Could not resolve dependencies: next goal: crypto-api (user goal) rejecting: crypto-api-0.13.2, 0.13, 0.12.2.2, 0.12.2.1, 0.12.2, 0.12.1, 0.12, 0.11, 0.10.2, 0.10.1, 0.10, 0.9, 0.8, 0.7, 0.6.4, 0.6.3, 0.6.2.1, 0.6.2, 0.6.1, 0.6, 0.5.2, 0.5, 0.4.1 (global constraint requires ==0.4) trying: crypto-api-0.4 trying: base-4.8.1.0/installed-4f7... (dependency of crypto-api-0.4) next goal: cereal (dependency of crypto-api-0.4) rejecting: cereal-0.5.1.0, 0.5.0.0, 0.4.1.1, 0.4.1.0, 0.4.0.1, 0.4.0.0 (conflict: crypto-api => cereal>=0.2 && <0.4) trying: cereal-0.3.5.2 rejecting: cereal-0.3.5.2:+split-base (conflict: base==4.8.1.0/installed-4f7..., cereal-0.3.5.2:split-base => base>=4 && <4.7) rejecting: cereal-0.3.5.2:-split-base (conflict: base==4.8.1.0/installed-4f7..., cereal-0.3.5.2:split-base => base<3.0) Dependency tree exhaustively searched.