anchor.diff:  
     text = buildFromGitHub {
       version = 2;
  -    rev = "85c29909967d7f171f821e7a42e7b7af76fb9598";
  -    date = "2017-02-11";
  +    rev = "4687d739464a2d0af89a25be0318456e0776f3ef";
  +    date = "2017-02-23";
       owner = "golang";
       repo = "text";
  -    sha256 = "00r4ilb0g6p579rk9478k8q407dcy1bfspx1rrily9cvnw72qgw0";
  +    sha256 = "0x07rwa3ghynhpwyyrxs2m974gxsf6hdj331izazxhxijysl87bz";
       goPackagePath = "golang.org/x/text";
       goPackageAliases = [ "github.com/golang/text" ];
       excludedPackages = "cmd";
  
positive.code: 
    prometheus_common = buildFromGitHub {
      version = 2;
      date = "2017-01-09";
      rev = "dd2f054febf4a6c00f2343686efb775948a8bff4";
      owner = "prometheus";
      repo = "common";
      sha256 = "1rzwlcb29s60bngqscfbq4g10hxpmh6an008zwp94rhc7vlvgkfd";
      buildInputs = [
        logrus
        net
  
negative.code: 
    netlink = buildFromGitHub {
      version = 2;
      rev = "fe3b5664d23a11b52ba59bece4ff29c52772a56b";
      owner  = "vishvananda";
      repo   = "netlink";
      sha256 = "14lj51afzq2fhklcyc0v9z9sy134bjw0s9vcy29n37m2sa6paxcx";
      date = "2017-02-20";
      propagatedBuildInputs = [
        netns
      ];
  