anchor.diff:  
     grpc = buildFromGitHub {
       version = 3;
  -    date = "2017-06-14";
  -    rev = "834dbd54e05e578c44aa018d5fab8d17892f9d4d";
  +    date = "2017-06-16";
  +    rev = "c5c761dbca07f4d0efafd3f430a40dcdf1c1163f";
       owner = "grpc";
       repo = "grpc-go";
  -    sha256 = "18c20b7im3hicbrlh0bfgh1ssid67dgbjnhwnhz2kx613wi9phcj";
  +    sha256 = "0bd58im8z14lxc44ka6b46b0d1k2awlqdrhlcmnkabx4irzzn8zd";
       goPackagePath = "google.golang.org/grpc";
       goPackageAliases = [
         "github.com/grpc/grpc-go"
  
positive.code:   };
  
    speakeasy = buildFromGitHub {
      version = 2;
      date = "2017-04-17";
      rev = "4aabc24848ce5fd31929f7d1e4ea74d3709c14cd";
      owner = "bgentry";
      repo = "speakeasy";
      sha256 = "05w4vlyglkzgwhfp2ini4yd3l8zblpx8b5sfsy649hzh8mm5v68p";
    };
  
    spec = buildFromGitHub {
      version = 3;
      date = "2017-06-06";
      rev = "e81a13315ac92ce3e73075856c5cd50301695405";
      owner  = "go-openapi";
      repo   = "spec";
      sha256 = "0zn70za09sylf0z9484i2qmv013nsnlpabh5a6ria44shf6q0qsd";
      propagatedBuildInputs = [
        jsonpointer
        jsonreference
  
negative.code: 
    image-spec = buildFromGitHub {
      version = 3;
      rev = "d207df434d113728dc3373cb3a905f00b482a858";
      owner  = "opencontainers";
      repo   = "image-spec";
      sha256 = "16icx57ppmlmdrdzsf6y3zad3hdznmlzp5zsm5mm97cyigs6746f";
      date = "2017-06-16";
      propagatedBuildInputs = [
        errors
        go4
  