anchor.diff:  
       ] ++ nixpkgsOverlays;
   
  -    mobileGhcOverlay = import ./nixpkgs-overlays/mobile-ghc { inherit lib; };
  -
       forceStaticLibs = self: super: {
         darwin = super.darwin // {
           libiconv =
  
positive.code:           ${if system == "i686-linux" then "cabal2nix" else null} = pkgs.haskell.lib.dontCheck pkgs.cabal2nix;
          };
        } // config;
      });
  
      inherit (nixpkgs) lib fetchurl fetchgit fetchgitPrivate fetchFromGitHub;
  
  
negative.code:         in lib.mapAttrs (_: args: if args == null then null else nixpkgsFunc args) rec {
          simulator64 = {
            system = "x86_64-darwin";
            overlays = nixpkgsArgs.overlays ++ [ mobileGhcOverlay forceStaticLibs ];
            crossSystem = {
              useIosPrebuilt = true;
              # You can change config/arch/isiPhoneSimulator depending on your target:
  