anchor.diff:      extraPreHook = ''
         export PATH_LOCALE=${pkgs.darwin.locale}/share/locale
       '';
  -    overrides = self: super: (persistent self super) // {
  +    overrides = lib.composeExtensions persistent (self: super: {
         # Hack to make sure we don't link ncurses in bootstrap tools. The proper
         # solution is to avoid passing -L/nix-store/...-bootstrap-tools/lib,
         # quite a sledgehammer just to get the C runtime.
  
positive.code:            "--disable-curses"
           ];
        });
      };
    };
  
    stdenvDarwin = prevStage: let
  
negative.code:       dyld Libsystem CF cctools ICU libiconv locale
      ]);
  
      overrides = lib.composeExtensions persistent (self: super: {
        clang = cc;
        llvmPackages = super.llvmPackages // { clang = cc; };
        inherit cc;
  
        darwin = super.darwin // {
          xnu = super.darwin.xnu.override { python = super.python.override { configd = null; }; };
        };
      });
    };
  
    stagesDarwin = [
  