anchor.diff:      excludedPackages = "\\(test\\|benchmark\\|example\\|bridge\\)";
       meta.useUnstable = true;
       date = "2017-10-20";
  -
  -    preBuild = ''
  -      pushd go/src/$goPackagePath
  -      go list ./... | xargs go generate
  -      popd
  -    '';
     };
   
     etcd_client = etcd.override {
  
positive.code:     repo = "etcd";
      rev = "785a5a11edf826f8d3e3396c33bf38c717b6225e";
      sha256 = "1riqdqm02mj6yykzf5576rd159jl1ryzsidy51ml338a9f5dd9j9";
      nativeBuildInputs = [
        ugorji_go.bin
      ];
      propagatedBuildInputs = [
        bbolt
        btree
  
negative.code:       "raft/raftpb"
      ];
      buildInputs = [
      ];
      propagatedBuildInputs = [
        protobuf
  