Resolving dependencies... cabal: Could not resolve dependencies: next goal: leksah (user goal) rejecting: leksah-0.15.2.0, leksah-0.15.1.4, leksah-0.15.1.3, leksah-0.15.1.2, leksah-0.15.1.1, leksah-0.15.1.0, leksah-0.15.0.6, leksah-0.15.0.5, leksah-0.15.0.4, leksah-0.15.0.3, leksah-0.15.0.2, leksah-0.15.0.1, leksah-0.14.4.0, leksah-0.14.3.0, leksah-0.14.2.0, leksah-0.14.1.1, leksah-0.14.1.0, leksah-0.14.0.1, leksah-0.14.0.0, leksah-0.13.4.3, leksah-0.13.4.2, leksah-0.13.4.1, leksah-0.13.4.0, leksah-0.13.3.0, leksah-0.12.1.3, leksah-0.12.1.2, leksah-0.12.1.0, leksah-0.12.0.3, leksah-0.10.0.4, leksah-0.10.0.3, leksah-0.10.0.1 (constraint from user target requires ==0.10.0.0) trying: leksah-0.10.0.0 next goal: base (dependency of leksah-0.10.0.0) rejecting: base-4.9.0.0/installed-4.9... (conflict: leksah => base>=4.0.0.0 && <4.4) rejecting: 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) Dependency tree exhaustively searched.