Resolving dependencies... cabal: Could not resolve dependencies: next goal: sbv (user goal) rejecting: sbv-5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 4.4, 4.3, 4.2, 4.1, 4.0, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.10, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0 (global constraint requires ==1.4) trying: sbv-1.4 trying: base-4.8.1.0/installed-4f7... (dependency of sbv-1.4) next goal: strict-concurrency (dependency of sbv-1.4) rejecting: strict-concurrency-0.2.4.1 (conflict: base==4.8.1.0/installed-4f7..., strict-concurrency => base>=4 && <4.6) rejecting: strict-concurrency-0.2.4, 0.2.3, 0.2.2, 0.2.1, 0.2, 0.1 (conflict: sbv => strict-concurrency>=0.2.4.1) Dependency tree exhaustively searched.