anchor.diff:  
     grpc = buildFromGitHub {
       version = 3;
  -    rev = "v1.6.0";
  +    rev = "v1.5.2";
       owner = "grpc";
       repo = "grpc-go";
  -    sha256 = "1hwibykd1qhrvlzw8zx8878kc4hwn81rjkza2x47wigvw7mmslc1";
  +    sha256 = "b73b1b59a78445c0e8cfbef3720ed63b61d7aded45bcf7f14aff149c084e48a7";
       goPackagePath = "google.golang.org/grpc";
       goPackageAliases = [
         "github.com/grpc/grpc-go"
  
positive.code:     owner  = "mitchellh";
      repo   = "reflectwalk";
      sha256 = "1xpgzn3rgc222yz09nmn1h8xi2769x3b5cmb23wch0w43cj8inkz";
    };
  
    resumable = buildFromGitHub {
  
negative.code:       amber
        blackfriday
        cast
        chroma
        cobra
        cssmin
        emoji
  