anchor.diff:  { lib, stdenv, fetchurl, fetchFromGitHub, perl, curl, bzip2, sqlite, openssl ? null, xz
  -, pkgconfig, boehmgc, perlPackages, libsodium, aws-sdk-cpp, brotli
  +, pkgconfig, boehmgc, perlPackages, libsodium, aws-sdk-cpp, brotli, boost
   , autoreconfHook, autoconf-archive, bison, flex, libxml2, libxslt, docbook5, docbook5_xsl
   , libseccomp, busybox-sandbox-shell
   , hostPlatform, buildPlatform
  
positive.code:     };
    }) // { perl-bindings = perl-bindings { nix = nixStable; }; };
  
    nixUnstable = nix;
  /*
    nixUnstable = (lib.lowPrio (common rec {
      name = "nix-2.0${suffix}";
      suffix = "pre5968_a6c0b773";
      src = fetchFromGitHub {
        owner = "NixOS";
        repo = "nix";
        rev = "a6c0b773b72d4e30690e01f1f1dcffc28f2d9ea1";
        sha256 = "0i8wcblcjw3291ba6ki4llw3fgm8ylp9q52kajkyr58dih537346";
      };
      fromGit = true;
    })) // { perl-bindings = perl-bindings { nix = nixUnstable; }; };
  */
  
  }
  
negative.code:           (aws-sdk-cpp.override {
              apis = ["s3"];
              customMemoryManagement = false;
            })
        ++ lib.optional fromGit boost;
  
      propagatedBuildInputs = [ boehmgc ];
  
  