anchor.diff:  
     go-nats-streaming = buildFromGitHub {
       version = 3;
  -    rev = "88fd0ce51e45a3a711b737174fd951944c91f085";
  +    rev = "43723aa09c43cec839e43583df07b1940c9f7651";
       owner = "nats-io";
       repo = "go-nats-streaming";
  -    sha256 = "04ipfvpw1vr2ynf5lzz74bpjpfih9fplpkn5clcm096a2d71gb9l";
  +    sha256 = "10q6m9hj8xqw4ajvka3rggsq0adsa4ip9bnvgdqsml2fh9i7kg0f";
       propagatedBuildInputs = [
         go-nats
         nuid
         gogo_protobuf
       ];
  -    date = "2017-11-14";
  +    date = "2017-12-07";
     };
   
     go-netrc = buildFromGitHub {
  
positive.code: 
    teleport = buildFromGitHub {
      version = 3;
      rev = "v2.3.5";
      owner = "gravitational";
      repo = "teleport";
      sha256 = "7f8aa8819d26d371aa75aee0074580334dc6c517aae45021ffc487384e5692a9";
      nativeBuildInputs = [
        pkgs.protobuf-cpp
        protobuf.bin
  
negative.code: 
    bbolt = buildFromGitHub {
      version = 3;
      rev = "48ea1b39c25fc1bab3506fbc712ecbaa842c4d2d";
      owner  = "coreos";
      repo   = "bbolt";
      sha256 = "1iqyy7q9n8rrldx09jhrlh274m8ykyym79iyfynnzafjhwph451g";
      date = "2017-12-07";
      buildInputs = [
        sys
      ];
  