Resolving dependencies... cabal: Could not resolve dependencies: trying: record-aeson-0.1.1 (user goal) trying: base-4.9.0.0/installed-4.9... (dependency of record-aeson-0.1.1) next goal: base-prelude (dependency of record-aeson-0.1.1) rejecting: base-prelude-1.0.1.1, base-prelude-1.0.1, base-prelude-1, base-prelude-0.2 (conflict: record-aeson => base-prelude>=0.1.19 && <0.2) rejecting: base-prelude-0.1.21, base-prelude-0.1.20, base-prelude-0.1.19 (conflict: base==4.9.0.0/installed-4.9..., base-prelude => base>=4.6 && <4.9) rejecting: base-prelude-0.1.17, base-prelude-0.1.16, base-prelude-0.1.15, base-prelude-0.1.14, base-prelude-0.1.13, base-prelude-0.1.12, base-prelude-0.1.11, base-prelude-0.1.10, base-prelude-0.1.9, base-prelude-0.1.8, base-prelude-0.1.7, base-prelude-0.1.6, base-prelude-0.1.5, base-prelude-0.1.4, base-prelude-0.1.3, base-prelude-0.1.2, base-prelude-0.1.1, base-prelude-0.1.0, base-prelude-0.1.18 (conflict: record-aeson => base-prelude>=0.1.19 && <0.2) Dependency tree exhaustively searched.