anchor.diff:  }:
   
   let
  -  common = { version, sha256, dependencies-sha256, tomcat, openssl ? openssl }:
  +  common = { version, sha256, dependencies-sha256, tomcat, opensslPkg ? openssl }:
       let
         # compile the hadoop tarball from sources, it requires some patches
         binary-distributon = stdenv.mkDerivation rec {
  
positive.code:               mv $n $out/bin.wrapped/
                makeWrapper $out/bin.wrapped/$(basename $n) $n \
                  --prefix PATH : "${stdenv.lib.makeBinPath [ which jre bash coreutils ]}" \
                  --prefix JAVA_LIBRARY_PATH : "${stdenv.lib.makeLibraryPath [ openssl snappy zlib bzip2 ]}" \
                  --set JAVA_HOME "${jre}" \
                  --set HADOOP_PREFIX "$out"
              fi
  
negative.code:     sha256 = "1ahv67f3lwak3kbjvnk1gncq56z6dksbajj872iqd0awdsj3p5rf";
      dependencies-sha256 = "1lsr9nvrynzspxqcamb10d596zlnmnfpxhkd884gdiva0frm0b1r";
      tomcat = tomcat_6_0_48;
      opensslPkg = openssl_1_0_2;
    };
    hadoop_2_8 = common {
      version = "2.8.4";
      sha256 = "16c3ljhrzibkjn3y1bmjxdgf0kn60l23ay5hqpp7vpbnqx52x68w";
      dependencies-sha256 = "1j4f461487fydgr5978nnm245ksv4xbvskfr8pbmfhcyss6b7w03";
      tomcat = tomcat_6_0_48;
      opensslPkg = openssl_1_0_2;
    };
    hadoop_2_9 = common {
      version = "2.9.1";
      sha256 = "0qgmpfbpv7f521fkjy5ldzdb4lwiblhs0hyl8qy041ws17y5x7d7";
      dependencies-sha256 = "1d5i8jj5y746rrqb9lscycnd7acmxlkz64ydsiyqsh5cdqgy2x7x";
      tomcat = tomcat_6_0_48;
      opensslPkg = openssl_1_0_2;
    };
    hadoop_3_0 = common {
      version = "3.0.3";
  