anchor.diff:  
     nixUnstable = lib.lowPrio (callPackage common rec {
       name = "nix-2.4${suffix}";
  -    suffix = "pre7346_5e7ccdc9";
  +    suffix = "pre7534_b92f58f6";
   
       src = fetchFromGitHub {
         owner = "NixOS";
         repo = "nix";
  -      rev = "5e7ccdc9e3ddd61dc85e20c898001345bfb497a5";
  -      sha256 = "10jg0rq92xbigbbri7harn4b75blqaf6rjgq4hhvlnggf2w9iprg";
  +      rev = "b92f58f6d9e44f97002d1722bd77bad939824c1c";
  +      sha256 = "1p791961y5v04kpz37g6hm98f1ig7i34inxl9dcj3pbqhf5kicxg";
       };
   
       crates = fetchurl {
  -      url = "https://hydra.nixos.org/build/115942497/download/1/nix-vendored-crates-2.4pre20200403_3473b19.tar.xz";
  -      sha256 = "a83785553bb4bc5b28220562153e201ec555a00171466ac08b716f0c97aee45a";
  +      url = "https://hydra.nixos.org/build/118797694/download/1/nix-vendored-crates-2.4pre7534_b92f58f6.tar.xz";
  +      sha256 = "a4c2612bbd81732bbb899bc0c230e07b16f6b6150ffbb19c4907dedbbc2bf9fc";
       };
   
       inherit storeDir stateDir confDir boehmgc;
  
positive.code:   , pkgconfig, boehmgc, perlPackages, libsodium, brotli, boost, editline, nlohmann_json
    , autoreconfHook, autoconf-archive, bison, flex, libxml2, libxslt, docbook5, docbook_xsl_ns
    , jq, libarchive, rustc, cargo
    , busybox-sandbox-shell
    , storeDir
    , stateDir
  
negative.code: 
        nativeBuildInputs =
          [ pkgconfig ]
          ++ lib.optionals is24 [ autoreconfHook autoconf-archive bison flex libxml2 libxslt
                                  docbook5 docbook_xsl_ns jq gmock ];
  
        buildInputs =
          [ curl openssl sqlite xz bzip2 nlohmann_json
  