anchor.diff:  
     sources = {
       "5.5" = {
  -      version = "5.5.2";
  -      sha1Confirm = "91b3b3c823fafce54609ed5c9075d9cf50b2edff";
  -      sha256 = "0870e2c0c72e6eda976effa07aa1cdd06a9500302320b5c22ed292ce21665bf1";
  +      version = "5.6.1";
  +      sha256 = "006f9cb3886877df845e3c3dea8a688777fb739a862d3afe1a113c16a732715f";
       };
       "6.0" = {
         version = "6.0.0-beta2";
  -      sha1Confirm = "c3f7c1685fc4925a4fac96fa4dfb1706c85acde6";
         sha256 = "0c200154c4980ad6e278d9c9ee9e2ca22d2c501c4c67e6fe748adde31aa36b0e";
       };
     };
  
positive.code: 
    src = fetchurl {
      url = "https://artifacts.elastic.co/downloads/elasticsearch/${name}.tar.gz";
      inherit (source) sha1Confirm sha256;
    };
  
    nativeBuildInputs = [
  
negative.code:       --set JAVA_HOME "${openjdk}"
    '';
  
    passthru = {
      srcVerification = fetchurl {
        inherit (src)
          outputHash
          outputHashAlgo
          urls;
        sha1Url = map (n: "${n}.sha1") src.urls;
        failEarly = true;
      };
    };
  
    meta = with lib; {
      description = "Distributed RESTful search engine built on top of Lucene";
      homepage = https://www.elastic.co/products/elasticsearch;
  