Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: ridley-extras-0.1.4.0 (user goal) [__1] trying: transformers-0.6.1.0/installed-0.6.1.0 (dependency of ridley-extras) [__2] trying: ridley-0.3.4.1 (dependency of ridley-extras) [__3] trying: time-1.12.2/installed-1.12.2 (dependency of ridley) [__4] trying: template-haskell-2.20.0.0/installed-2.20.0.0 (dependency of ridley) [__5] trying: pretty-1.1.3.6/installed-1.1.3.6 (dependency of template-haskell) [__6] trying: prometheus-2.2.4 (dependency of ridley-extras) [__7] trying: katip-0.8.8.0 (dependency of ridley-extras) [__8] trying: aeson-2.2.1.0 (dependency of katip) [__9] next goal: th-abstraction (dependency of aeson) [__9] rejecting: th-abstraction-0.7.0.0 (conflict: aeson => th-abstraction>=0.5.0.0 && <0.7) [__9] trying: th-abstraction-0.6.0.0 [_10] trying: semialign-1.3 (dependency of aeson) [_11] trying: semialign:+semigroupoids [_12] trying: semigroupoids-6.0.0.1 (dependency of semialign +semigroupoids) [_13] trying: primitive-0.9.0.0 (dependency of aeson) [_14] next goal: ekg-prometheus-adapter (dependency of ridley-extras) [_14] rejecting: ekg-prometheus-adapter-0.1.0.4 (conflict: transformers==0.6.1.0/installed-0.6.1.0, ekg-prometheus-adapter => transformers<0.6.0.0) [_14] skipping: ekg-prometheus-adapter-0.1.0.3, ekg-prometheus-adapter-0.1.0.2 (has the same characteristics that caused the previous version to fail: excludes 'transformers' version 0.6.1.0) [_14] rejecting: ekg-prometheus-adapter-0.1.0.1 (conflict: ridley => ekg-prometheus-adapter>=0.1.0.3) [_14] skipping: ekg-prometheus-adapter-0.1.0.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=0.1.0.3' from 'ridley') [_14] fail (backjumping, conflict set: ekg-prometheus-adapter, ridley, ridley-extras, transformers) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: aeson, katip, base, th-abstraction, template-haskell, semigroupoids, ridley-extras, semialign, semialign:semigroupoids, time, pretty, transformers, prometheus, ekg-prometheus-adapter, primitive, ridley Try running with --minimize-conflict-set to improve the error message.