Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: moffy-samples-gtk3-0.1.0.0 (user goal) [__1] next goal: moffy-samples-gtk3-run (dependency of moffy-samples-gtk3) [__1] rejecting: moffy-samples-gtk3-run-0.1.0.2, moffy-samples-gtk3-run-0.1.0.1, moffy-samples-gtk3-run-0.1.0.0 (conflict: pkg-config package gtk+-3.0-any, not found in the pkg-config database) [__1] fail (backjumping, conflict set: moffy-samples-gtk3, moffy-samples-gtk3-run) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: moffy-samples-gtk3-run, moffy-samples-gtk3