Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: atlassian-connect-core-0.10.1.0 (user goal) [__1] trying: network-api-support-0.3.5 (dependency of atlassian-connect-core) [__2] next goal: tls (dependency of network-api-support) [__2] rejecting: tls-1.7.1 (conflict: network-api-support => tls>=1.2.0 && <1.5) [__2] skipping: tls-1.7.0, tls-1.6.0, tls-1.5.8, tls-1.5.7, tls-1.5.6, tls-1.5.5, tls-1.5.4, tls-1.5.3, tls-1.5.2, tls-1.5.1, tls-1.5.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=1.2.0 && <1.5' from 'network-api-support') [__2] trying: tls-1.4.1 [__3] trying: x509-1.7.7 (dependency of tls) [__4] trying: async-2.2.4 (dependency of tls) [__5] next goal: base (dependency of atlassian-connect-core) [__5] rejecting: base-4.16.3.0/installed-4.16.3.0 (conflict: tls => base>=4.7 && <4.13) [__5] skipping: base-4.18.0.0, base-4.17.1.0, base-4.17.0.0, base-4.16.4.0, base-4.16.3.0, base-4.16.2.0, base-4.16.1.0, base-4.16.0.0, base-4.15.1.0, base-4.15.0.0, base-4.14.3.0, base-4.14.2.0, base-4.14.1.0, base-4.14.0.0, base-4.13.0.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=4.7 && <4.13' from 'tls') [__5] rejecting: base-4.12.0.0, 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) [__5] fail (backjumping, conflict set: atlassian-connect-core, base, tls) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: network-api-support, base, tls, atlassian-connect-core, x509, async Try running with --minimize-conflict-set to improve the error message.