anchor.diff:              jsaddle = self.callCabal2nix "jsaddle" "${jsaddle-src}/jsaddle" {};
               jsaddle-dom = self.callCabal2nix "jsaddle-dom" jsaddle-dom-src {};
               jsaddle-warp = dontCheck (self.callCabal2nix "jsaddle-warp" "${jsaddle-src}/jsaddle-warp" {});
  +            jsaddle-webkit2gtk = self.callCabal2nix "jsaddle-webkit2gtk" "${jsaddle-src}/jsaddle-webkit2gtk" {};
               ghcjs-dom-jsaddle = self.callCabal2nix "ghcjs-dom-jsaddle" "${ghcjs-dom-src}/ghcjs-dom-jsaddle" {};
               ghcjs-dom-jsffi = self.callCabal2nix "ghcjs-dom-jsffi" "${ghcjs-dom-src}/ghcjs-dom-jsffi" {};
               ghcjs-dom = self.callCabal2nix "ghcjs-dom" "${ghcjs-dom-src}/ghcjs-dom" {};
  
positive.code:   jsaddle-src = pkgs.fetchFromGitHub {
      owner = "ghcjs";
      repo = "jsaddle";
      rev = "1e39844";
      sha256 = "1qrjrjagmrrlcalys33636w5cb67db52i183masb7xd93wir8963";
    };
    jsaddle-dom-src = pkgs.fetchFromGitHub {
      owner = "ghcjs";
  
negative.code:             miso-jsaddle = self.callCabal2nixWithOptions "miso" miso-src-filter "-fjsaddle" {};
              miso-examples-jsaddle = self.callCabal2nixWithOptions "miso-examples" miso-examples-src-filter "-fjsaddle" { miso = miso-jsaddle; };
              jsaddle-warp = dontCheck (self.callCabal2nix "jsaddle-warp" "${jsaddle-src}/jsaddle-warp" {});
              webkit2gtk3-javascriptcore = self.callCabal2nix "webkit2gtk3-javascriptcore" webkit2gtk3-javascriptcore-src {};
              jsaddle-webkit2gtk = self.callCabal2nix "jsaddle-webkit2gtk" "${jsaddle-src}/jsaddle-webkit2gtk" {};
              ghcjs-dom-jsaddle = self.callCabal2nix "ghcjs-dom-jsaddle" "${ghcjs-dom-src}/ghcjs-dom-jsaddle" {};
              ghcjs-dom-jsffi = self.callCabal2nix "ghcjs-dom-jsffi" "${ghcjs-dom-src}/ghcjs-dom-jsffi" {};
              ghcjs-dom = self.callCabal2nix "ghcjs-dom" "${ghcjs-dom-src}/ghcjs-dom" {};
  