anchor.diff:  
     sys = buildFromGitHub {
       version = 2;
  -    rev = "aaabbdc969c3935a2a7f61efac801e7163c73a2a";
  +    rev = "e24f485414aeafb646f6fca458b0bf869c0880a1";
       date = "2017-02-10";
       owner  = "golang";
       repo   = "sys";
  -    sha256 = "13ryidi102rksybvz30d58qn22jjdx9m1nmqz2c03c9vvb49m9cx";
  +    sha256 = "0cc213v5jyxn773wdmanqzd08qhy14a890314x1hivcs6ysrw7iv";
       goPackagePath = "golang.org/x/sys";
       goPackageAliases = [
         "github.com/golang/sys"
  
positive.code: 
    dns = buildFromGitHub {
      version = 2;
      rev = "4e953232d8083f240dff0ac425afcba18bb5b722";
      date = "2017-02-07";
      owner  = "miekg";
      repo   = "dns";
      sha256 = "101xc235k168id0f7xk7wrdlnrxh87mzjlyck6da875rwic41ggy";
    };
  
    weppos-dnsimple-go = buildFromGitHub {
  
negative.code: 
    gomega = buildFromGitHub {
      version = 2;
      rev = "c463cd2a8578290d4be7a25cba69de81cf35785e";
      owner  = "onsi";
      repo   = "gomega";
      sha256 = "1b8gf1s08iah061x908p8rh01y531l67ijcrlhy6dsmrrp38d23y";
      propagatedBuildInputs = [
        protobuf
        yaml_v2
      ];
      date = "2017-02-13";
    };
  
    google-api-go-client = buildFromGitHub {
      version = 2;
      rev = "bc20c61134e1d25265dd60049f5735381e79b631";
      date = "2017-02-10";
      owner = "google";
      repo = "google-api-go-client";
      sha256 = "02ps3cxzg6x5xwam4qp065cgrps1ggrcnxjfngx84wvsvy9d0ybb";
      goPackagePath = "google.golang.org/api";
      buildInputs = [
        genproto
  