Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: cryptoids-types-1.0.0.1 (user goal) [__1] trying: path-pieces-0.2.1 (dependency of cryptoids-types) [__2] next goal: text (dependency of path-pieces) [__2] rejecting: text-2.1.1/installed-inplace (conflict: cryptoids-types => deepseq>=1.4.3.0 && <1.5, text => deepseq==1.5.1.0/installed-inplace) [__2] trying: text-2.1.2 [__3] trying: template-haskell-2.21.0.0/installed-inplace (dependency of text) [__4] next goal: pretty (dependency of template-haskell) [__4] rejecting: pretty-1.1.3.6/installed-inplace (conflict: cryptoids-types => deepseq>=1.4.3.0 && <1.5, pretty => deepseq==1.5.1.0/installed-inplace) [__4] rejecting: pretty-1.1.3.6, pretty-1.1.3.5, pretty-1.1.3.4, pretty-1.1.3.3, pretty-1.1.3.2, pretty-1.1.3.1, pretty-1.1.2.1, pretty-1.1.2.0, pretty-1.1.1.3, pretty-1.1.1.2, pretty-1.1.1.1, pretty-1.1.1.0, pretty-1.1.0.0, pretty-1.0.1.2, pretty-1.0.1.1, pretty-1.0.1.0, pretty-1.0.0.0 (conflict: template-haskell => pretty==1.1.3.6/installed-inplace) [__4] fail (backjumping, conflict set: cryptoids-types, pretty, template-haskell) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: base, text, template-haskell, bytestring, pretty, cryptoids-types, path-pieces Try running with --minimize-conflict-set to improve the error message.