anchor.diff:  
     grpc = buildFromGitHub {
       version = 2;
  -    rev = "590256047f42067a8c96e0e7fd497d3896dc041a";
  +    rev = "c2983be903f6966c83c6ea86ba74df0b7cc882cd";
       owner = "grpc";
       repo = "grpc-go";
  -    sha256 = "0gsg5qqisaz015fxczzrlj2s4k0pbrs8y23g06ssrs9syz5yw417";
  +    sha256 = "1gip3wysqls51gx9c3iyzbmfsbq96m095ksw3z31hmwf5n0n7c5j";
       goPackagePath = "google.golang.org/grpc";
       goPackageAliases = [ "github.com/grpc/grpc-go" ];
       propagatedBuildInputs = [ http2 net protobuf oauth2 glog ];
       excludedPackages = "\\(test\\|benchmark\\)";
       meta.useUnstable = true;
  -    date = "2016-09-26";
  +    date = "2016-09-29";
     };
   
     grpc-gateway = buildFromGitHub {
  
positive.code: 
    yaml_v2 = buildFromGitHub {
      version = 2;
      rev = "31c299268d302dd0aa9a0dcf765a3d58971ac83f";
      date = "2016-09-12";
      owner = "go-yaml";
      repo = "yaml";
      sha256 = "0k2jasi5fqz114iqy0z5dwg77gf4zch14vh59njjynh1gn6gyrzz";
      goPackagePath = "gopkg.in/yaml.v2";
    };
  
  
negative.code: 
    net = buildFromGitHub {
      version = 2;
      rev = "a333c534c871727fb95745870e8b98a69447f2ce";
      date = "2016-09-29";
      owner  = "golang";
      repo   = "net";
      sha256 = "0j09wvllnpy2ycbqdrc222f4afdkdsprkzipai70wzq7xi4rh6mr";
      goPackagePath = "golang.org/x/net";
      goPackageAliases = [
        "code.google.com/p/go.net"
  