Resolving dependencies... cabal: Could not resolve dependencies: [__0] trying: gargoyle-postgresql-connect-0.1.0.0 (user goal) [__1] next goal: gargoyle-postgresql-nix (dependency of gargoyle-postgresql-connect) [__1] rejecting: gargoyle-postgresql-nix-0.3.0.0 (conflict: gargoyle-postgresql-connect => gargoyle-postgresql-nix==0.3) [__1] fail (backjumping, conflict set: gargoyle-postgresql-connect, gargoyle-postgresql-nix) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: gargoyle-postgresql-connect, gargoyle-postgresql-nix