anchor.diff:  
     sync = buildFromGitHub {
       version = 3;
  -    rev = "57af736625aaa69dfa099432bb67e0808eef3bcc";
  -    date = "2017-05-10";
  +    rev = "f52d1811a62927559de87708c8913c1650ce4f26";
  +    date = "2017-05-17";
       owner  = "golang";
       repo   = "sync";
  -    sha256 = "1d55vjzhd9m85hlkljxswcfsp3lqfhxf70k9hvlr7mm6ac0yykyr";
  +    sha256 = "1lrlz11mqkc81s4wj9vagyfvdql8ngq5ipw6wk09m9i8kj57ws9i";
       goPackagePath = "golang.org/x/sync";
       propagatedBuildInputs = [
         net
  
positive.code: 
    oauth2 = buildFromGitHub {
      version = 3;
      rev = "ad516a297a9f2a74ecc244861b298c94bdd28b9d";
      date = "2017-05-10";
      owner = "golang";
      repo = "oauth2";
      sha256 = "0v050j5sxv55gzpmgy5a5ihd5abc9znffk2n9szkj89bs01cpyys";
      goPackagePath = "golang.org/x/oauth2";
      propagatedBuildInputs = [
        appengine
  
negative.code: 
    sys = buildFromGitHub {
      version = 3;
      rev = "a2e06a18b0d52d8cb2010e04b372a1965d8e3439";
      date = "2017-05-18";
      owner  = "golang";
      repo   = "sys";
      sha256 = "0wh0a9asbqgpisihfxj20ndzrbhgg7bm3xyg7qf0v4nw3hffaz7a";
      goPackagePath = "golang.org/x/sys";
    };
  
  