anchor.diff:  
     nixUnstable = (lib.lowPrio (common rec {
       name = "nix-1.12${suffix}";
  -    suffix = "pre5511_c94f3d55";
  +    suffix = "pre5619_346aeee1";
       src = fetchFromGitHub {
         owner = "NixOS";
         repo = "nix";
  -      rev = "c94f3d5575d7af5403274d1e9e2f3c9d72989751";
  -      sha256 = "1akfzzm4f07wj6l7za916xv5rnh71pk3vl8dphgradjfqb37bv18";
  +      rev = "346aeee1cb21b5cab5ddc3e8658c88321f513761";
  +      sha256 = "0lyrs0mqnh89w1nzrqpxvnh7bdjpg8j22xaidql47f1nwbblmn3f";
       };
       fromGit = true;
     })) // { perl-bindings = perl-bindings { nix = nixUnstable; }; };
  
positive.code: { lib, stdenv, fetchurl, fetchFromGitHub, perl, curl, bzip2, sqlite, openssl ? null, xz
  , pkgconfig, boehmgc, perlPackages, libsodium, aws-sdk-cpp, brotli, readline
  , autoreconfHook, autoconf-archive, bison, flex, libxml2, libxslt, docbook5, docbook5_xsl
  , libseccomp, busybox
  , hostPlatform
  , storeDir ? "/nix/store"
  , stateDir ? "/nix/var"
  
negative.code: 
      buildInputs = [ curl openssl sqlite xz ]
        ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
        ++ lib.optionals fromGit [ brotli readline nlohmann_json ] # Since 1.12
        ++ lib.optional stdenv.isLinux libseccomp
        ++ lib.optional ((stdenv.isLinux || stdenv.isDarwin) && is112)
            (aws-sdk-cpp.override {
  