anchor.diff:  
     grpc = buildFromGitHub {
       version = 2;
  -    rev = "c2983be903f6966c83c6ea86ba74df0b7cc882cd";
  +    rev = "b1a2821ca5a4fd6b6e48ddfbb7d6d7584d839d21";
       owner = "grpc";
       repo = "grpc-go";
  -    sha256 = "1gip3wysqls51gx9c3iyzbmfsbq96m095ksw3z31hmwf5n0n7c5j";
  +    sha256 = "0505jxz46mx7yn4ihx3ar6xh628yf7gha9afx1szlwcm3klv77rb";
       goPackagePath = "google.golang.org/grpc";
       goPackageAliases = [ "github.com/grpc/grpc-go" ];
       propagatedBuildInputs = [ http2 net protobuf oauth2 glog ];
       excludedPackages = "\\(test\\|benchmark\\)";
       meta.useUnstable = true;
  -    date = "2016-09-29";
  +    date = "2016-10-03";
     };
   
     grpc-gateway = buildFromGitHub {
  
positive.code: 
    text = buildFromGitHub {
      version = 2;
      rev = "a7c023693a94aedd6b6df43ae7526bfe9d2b7d22";
      date = "2016-09-22";
      owner = "golang";
      repo = "text";
      sha256 = "002r51abslnm7d4mgvgq9nxgrm7mbh009mk8l1abgj11safzxf2v";
      goPackagePath = "golang.org/x/text";
      goPackageAliases = [ "github.com/golang/text" ];
      excludedPackages = "cmd";
  
negative.code: 
    go-multiaddr-net = buildFromGitHub {
      version = 2;
      rev = "97164e677cc0cba05d67defc077f9921bfd85df8";
      owner  = "multiformats";
      repo   = "go-multiaddr-net";
      sha256 = "1rr33nb744cg86ndxy74g32ixzbx5584mh0162cvvxyja7rks1r7";
      date = "2016-10-03";
      goPackageAliases = [ "github.com/jbenet/go-multiaddr-net" ];
      propagatedBuildInputs = [
        go-multiaddr
  