anchor.diff:  
   let
     common = { pname, version, untarDir ? "${pname}-${version}", sha256, jdk, openssl ? null, nativeLibs ? [ ], libPatches ? "" }:
  -    let
  -      platformUrlSuffix = optionalString stdenv.isAarch64 "-aarch64";
  -    in
       stdenv.mkDerivation rec {
         inherit pname version jdk libPatches untarDir openssl;
         src = fetchurl {
  -        url = "mirror://apache/hadoop/common/hadoop-${version}/hadoop-${version}${platformUrlSuffix}.tar.gz";
  +        url = "mirror://apache/hadoop/common/hadoop-${version}/hadoop-${version}" + optionalString stdenv.isAarch64 "-aarch64" + ".tar.gz";
           sha256 = sha256.${stdenv.system};
         };
         doCheck = true;
  
positive.code:           computers, each of which may be prone to failures.
          '';
          maintainers = with maintainers; [ volth illustris ];
          platforms = builtins.attrNames sha256;
        };
  
      };
  in
  {
  
negative.code:   hadoop2 = common rec {
      pname = "hadoop";
      version = "2.10.1";
      sha256.x86_64-linux = "1w31x4bk9f2swnx8qxx0cgwfg8vbpm6cy5lvfnbbpl3rsjhmyg97";
      jdk = jdk8_headless;
    };
  }
  