Resolving dependencies... cabal: Could not resolve dependencies: [__0] trying: restful-snap-0.4.1 (user goal) [__1] next goal: snap (dependency of restful-snap) [__1] rejecting: snap-1.1.1.0, snap-1.1.0.0 (conflict: restful-snap => snap>=0.11 && <1.1) [__1] trying: snap-1.0.0.2 [__2] next goal: directory (dependency of snap) [__2] rejecting: directory-1.3.1.5/installed-1.3... (conflict: snap => base>=4 && <4.11, directory => base==4.11.1.0/installed-4.1...) [__2] trying: directory-1.3.3.0 [__3] next goal: base (dependency of restful-snap) [__3] rejecting: base-4.11.1.0/installed-4.1... (conflict: snap => base>=4 && <4.11) [__3] rejecting: base-4.11.1.0, base-4.11.0.0, base-4.10.1.0, base-4.10.0.0, base-4.9.1.0, base-4.9.0.0, base-4.8.2.0, base-4.8.1.0, base-4.8.0.0, base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1, base-4.6.0.0, base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0, base-4.3.1.0, base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0, base-4.1.0.0, base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from non-upgradeable package requires installed instance) [__3] fail (backjumping, conflict set: base, restful-snap, snap) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: snap, directory, base, restful-snap