anchor.diff:        inherit name src;
         version = lib.getVersion name;
   
  -      is30 = lib.versionAtLeast version "3.0pre";
  -      isExactly30 = lib.versionAtLeast version "2.3" && lib.versionOlder version "3.0";
  +      is24 = lib.versionAtLeast version "2.4pre";
  +      isExactly24 = lib.versionAtLeast version "2.4" && lib.versionOlder version "2.4";
   
         VERSION_SUFFIX = suffix;
   
  
positive.code:             patchelf --set-rpath $out/lib:${stdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
            ''}
          '' +
          # For Nix 3.0, patch around an issue where the Nix configure step pulls in the
          # build system's bash and other utilities when cross-compiling
          lib.optionalString (stdenv.buildPlatform != stdenv.hostPlatform && isExactly30) ''
            mkdir tmp/
            substitute corepkgs/config.nix.in tmp/config.nix.in \
              --subst-var-by bash ${bash}/bin/bash \
  
negative.code:   });
  
    nixUnstable = lib.lowPrio (callPackage common rec {
      name = "nix-2.4${suffix}";
      suffix = "pre20201102_550e11f";
  
      src = fetchFromGitHub {
        owner = "NixOS";
        repo = "nix";
        rev = "550e11f077ae508abde5a33998a9d4029880e7b2";
        sha256 = "186grfxsfqg7r92wgwbma66xc7p3iywn43ff7s59m4g6bvb0qgcl";
      };
  
      inherit storeDir stateDir confDir boehmgc;
  