Resolving dependencies... cabal: Could not resolve dependencies: next goal: github-release (user goal) rejecting: github-release-1.1.2, github-release-1.1.1, github-release-1.1.0, github-release-1.0.7, github-release-1.0.6, github-release-1.0.5, github-release-1.0.4, github-release-1.0.3, github-release-1.0.2, github-release-1.0.1, github-release-1.0.0, github-release-0.2.0, github-release-0.1.9, github-release-0.1.8, github-release-0.1.7, github-release-0.1.6 (constraint from user target requires ==0.1.5) trying: github-release-0.1.5 next goal: base (dependency of github-release-0.1.5) rejecting: base-4.10.1.0/installed-4.1... (conflict: github-release => base>=4.8.2.0 && <4.9) rejecting: 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) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: base, github-release