anchor.diff:      rm -v $out/lib/libx265.a
     '';
   
  +  passthru = {
  +    srcVerification = fetchurl {
  +      inherit (src)
  +        outputHash
  +        outputHashAlgo
  +        urls;
  +      fullOpts = {
  +        md5Confirm = source.md5confirm;
  +      };
  +      failEarly = true;
  +    };
  +  };
  +
     meta = with lib; {
       description = "Library for encoding h.265/HEVC video streams";
       homepage = http://x265.org;
  
positive.code:       }
      else
        fetchurl {
          url = "https://bitbucket.org/multicoreware/x265/downloads/"
            + "x265_${source.version}.tar.gz";
          inherit (source) multihash sha256;
        };
  
  
negative.code:   sources = {
      "stable" = {
        version = "3.0";
        md5confirm = "8ff1780246bb7ac8506239f6129c04ec";
        multihash = "QmTRoGtatifcPPHjL22njyYSn381wb6wJsrrDzZXtVMjm7";
        sha256 = "c5b9fc260cabbc4a81561a448f4ce9cad7218272b4011feabc3a6b751b2f0662";
      };
      "head" = {
  