Resolving dependencies... cabal: Could not resolve dependencies: next goal: swish (user goal) rejecting: swish-0.9.1.7, swish-0.9.1.6, swish-0.9.1.5, swish-0.9.1.3, swish-0.9.1.2, swish-0.9.1.1, swish-0.9.1.0, swish-0.9.0.15, swish-0.9.0.14, swish-0.9.0.13, swish-0.9.0.12, swish-0.9.0.11, swish-0.9.0.10, swish-0.9.0.9, swish-0.9.0.8, swish-0.9.0.7, swish-0.9.0.6, swish-0.9.0.5, swish-0.9.0.4, swish-0.9.0.3, swish-0.9.0.2, swish-0.9.0.1, swish-0.9.0.0, swish-0.8.0.3, swish-0.8.0.2, swish-0.8.0.0, swish-0.7.0.2, swish-0.7.0.1, swish-0.7.0.0, swish-0.6.5.2, swish-0.6.5.1, swish-0.6.5.0, swish-0.6.4.0, swish-0.6.3.0, swish-0.6.2.1, swish-0.6.1.2, swish-0.6.1.1, swish-0.6.1.0, swish-0.6.0.1, swish-0.6.0.0, swish-0.5.0.3, swish-0.5.0.2, swish-0.5.0.1, swish-0.5.0.0, swish-0.4.0.0, swish-0.3.2.1, swish-0.3.2.0, swish-0.3.1.2, swish-0.3.1.1, swish-0.3.1.0, swish-0.3.0.3, swish-0.3.0.2, swish-0.3.0.1, swish-0.3.0.0 (constraint from user target requires ==0.2.1) trying: swish-0.2.1 next goal: base (dependency of swish-0.2.1) rejecting: base-4.9.0.0/installed-4.9... (conflict: swish => base>3 && <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.