anchor.diff:    };
   
     go-events = buildFromGitHub {
  -    version = 2;
  +    version = 3;
       owner = "docker";
       repo = "go-events";
  -    rev = "aa2e3b613fbbfdddbe055a7b9e3ce271cfd83eca";
  -    date = "2016-09-06";
  -    sha256 = "9a343e28d608971d2baec59bc62637a697f1b45c44e61b782b81c212b5ef507b";
  +    rev = "9461782956ad83b30282bf90e31fa6a70c255ba9";
  +    date = "2017-07-21";
  +    sha256 = "1x902my10kmp3d24jcd9pxpbhma95jyqdd1k4ndjmcc6z4ygxxz1";
       propagatedBuildInputs = [
         logrus
       ];
  
positive.code: 
    tools = buildFromGitHub {
      version = 3;
      rev = "fcc44a6330868f7bdb7285effa1a0666eede46ac";
      date = "2017-08-01";
      owner = "golang";
      repo = "tools";
      sha256 = "14nmp27wj4xi4bjwk7rqblrs2yiyynvm6nfaqgayl9zl26zgav3f";
      goPackagePath = "golang.org/x/tools";
  
      preConfigure = ''
  
negative.code: 
    gocql = buildFromGitHub {
      version = 3;
      rev = "db941d937da2750f2b9392ccafd3384a25c42cd5";
      owner  = "gocql";
      repo   = "gocql";
      sha256 = "0bdjh491yij2mb73dxwy97xhzmzrvl43h09fii2pm5i43932zp3y";
      propagatedBuildInputs = [
        inf_v0
        snappy
        hailocab_go-hostpool
        net
      ];
      date = "2017-08-02";
    };
  
    gofuzz = buildFromGitHub {
  