anchor.diff:    # https://cwiki.apache.org/confluence/display/HADOOP/Hadoop+Java+Versions
     hadoop_3_3 = common rec {
       pname = "hadoop";
  -    version = "3.3.1";
  +    versions = rec {
  +      x86_64-linux = "3.3.3";
  +      x86_64-darwin = x86_64-linux;
  +      aarch64-linux = "3.3.1";
  +      aarch64-darwin = aarch64-linux;
  +    };
       untarDir = "${pname}-${version}";
  -    sha256 = rec {
  -      x86_64-linux = "1b3v16ihysqaxw8za1r5jlnphy8dwhivdx2d0z64309w57ihlxxd";
  +    hash = rec {
  +      x86_64-linux = "sha256-+nHGG7qkJxKa7wn+wCizTdVCxlrZD9zOxefvk9g7h2Q=";
         x86_64-darwin = x86_64-linux;
  -      aarch64-linux = "00ln18vpi07jq2slk3kplyhcj8ad41n0yl880q5cihilk7daclxz";
  +      aarch64-linux = "sha256-v1Om2pk0wsgKBghRD2wgTSHJoKd3jkm1wPKAeDcKlgI=";
         aarch64-darwin = aarch64-linux;
       };
       jdk = jdk11_headless;
  
positive.code:   };
    hadoop2 = common rec {
      pname = "hadoop";
      version = "2.10.1";
      sha256.x86_64-linux = "1w31x4bk9f2swnx8qxx0cgwfg8vbpm6cy5lvfnbbpl3rsjhmyg97";
      jdk = jdk8_headless;
      tests = nixosTests.hadoop2;
    };
  
negative.code: assert elem stdenv.system [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];
  
  let
    common = { pname, versions, untarDir ? "${pname}-${version}", hash, jdk, openssl ? null, nativeLibs ? [ ], libPatches ? "", tests }:
      stdenv.mkDerivation rec {
        inherit pname jdk libPatches untarDir openssl;
        version = versions.${stdenv.system};
        src = fetchurl {
          url = "mirror://apache/hadoop/common/hadoop-${version}/hadoop-${version}" + optionalString stdenv.isAarch64 "-aarch64" + ".tar.gz";
          hash = hash.${stdenv.system};
        };
        doCheck = true;
  
  