anchor.diff:  
     grpc = buildFromGitHub {
       version = 2;
  -    date = "2017-02-14";
  -    rev = "cbcceb2942a489498cf22b2f918536e819d33f0a";
  +    date = "2017-02-15";
  +    rev = "d0c32ee6a441117d49856d6120ca9552af413ee0";
       owner = "grpc";
       repo = "grpc-go";
  -    sha256 = "0pp1igmiw6gi8aaynw52j1ai7vz94ij9lwnkdgqi9cwdwlg8byhf";
  +    sha256 = "0idijjxm1y8pj9gx85gp2z4xwrcw3apsdlkjk49w8pws4wak9xn9";
       goPackagePath = "google.golang.org/grpc";
       goPackageAliases = [
         "github.com/grpc/grpc-go"
  
positive.code:     version = 2;
      owner = "ncw";
      repo = "rclone";
      rev = "50e190ff54c9e3b94f6e1f48be5b66b5e113e561";
      sha256 = "1wj0a3v0ry2mkg4cd9wsma65wgc6nbyy4gh2jz6z5j6cx9c2h96c";
      propagatedBuildInputs = [
        aws-sdk-go
        cobra
  
negative.code: 
    google-cloud-go = buildFromGitHub {
      version = 2;
      date = "2017-02-16";
      rev = "0b87d14d90086b53a97dfbd66f3000f7f112b494";
      owner = "GoogleCloudPlatform";
      repo = "google-cloud-go";
      sha256 = "145fsk3v68faaf514v3yqz3lwgip1a3whwy637pds0i1w16dwdvk";
      goPackagePath = "cloud.google.com/go";
      goPackageAliases = [
        "google.golang.org/cloud"
  