anchor.diff:              };
           in {
           simulator64 = nixpkgsFunc {
  -          crossSystem = 
  +          crossSystem =
               let cfg = {
                 # You can change config/arch/isiPhoneSimulator depending on your target:
                 # aarch64-apple-darwin14 | arm64  | false
  
positive.code:   ghc7 = overrideForGhc7 (extendHaskellPackages nixpkgs.pkgs.haskell.packages.ghc7103);
    ghc7_8 = overrideForGhc7_8 (extendHaskellPackages nixpkgs.pkgs.haskell.packages.ghc784);
    ghcIosSimulator64 = overrideForGhcIOS (extendHaskellPackages nixpkgsCross.ios.simulator64.pkgs.haskell.packages.ghcCross);
    ghcIosArm64 = overrideForGhcIOS (extendHaskellPackages nixpkgsCross.ios.arm64.pkgs.haskell.packages.ghcCross);
    ghcIosArmv7 = overrideForGhcIOS (extendHaskellPackages nixpkgsCross.ios.armv7.pkgs.haskell.packages.ghcCross);
  in let this = rec {
  
negative.code:       if system == null then {} else { inherit system; }
      ));
      nixpkgsCross = {
        android = {
          arm64 = nixpkgsFunc {
            crossSystem =
              let cfg = {
                config = "aarch64-linux-android";
                arch = "arm64";
              }; in {
              inherit (cfg) config arch;
              libc = "glibc";
              withTLS = true;
              openssl.system = "linux-generic64";
              platform = nixpkgs.pkgs.platforms.aarch64-multiplatform;
            };
            config.allowUnfree = true;
          };
        };
        ios =
          let config = {
                allowUnfree = true;
                packageOverrides = p: {
  