Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: ghc-lib-parser-ex-9.8.0.0 (user goal) [__1] trying: ghc-lib-parser-ex:-auto [__2] trying: ghc-lib-parser-ex:-no-ghc-lib [__3] trying: ghc-lib-parser-9.8.1.20231009 (dependency of ghc-lib-parser-ex -auto -no-ghc-lib) [__4] next goal: base (dependency of ghc-lib-parser-ex) [__4] rejecting: base-4.16.3.0/installed-4.16.3.0 (conflict: ghc-lib-parser => base>=4.17.0.0 && <4.20) [__4] rejecting: base-4.19.0.0, base-4.18.1.0, base-4.18.0.0, base-4.17.2.0, 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, 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) [__4] fail (backjumping, conflict set: base, ghc-lib-parser, ghc-lib-parser-ex) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: ghc-lib-parser-ex, ghc-lib-parser-ex:auto, ghc-lib-parser-ex:no-ghc-lib, ghc-lib-parser, base Try running with --minimize-conflict-set to improve the error message.