anchor.diff:  
     crypto = buildFromGitHub {
       version = 3;
  -    rev = "e1a4589e7d3ea14a3352255d04b6f1a418845e5e";
  -    date = "2017-06-01";
  +    rev = "e7ba82683099cae71475961448ab8f903ea77c26";
  +    date = "2017-06-06";
       owner    = "golang";
       repo     = "crypto";
  -    sha256 = "17bmnj04hpb53yi3m5j2y6j7sb30123miz3q601qdzvv0b2rnkca";
  +    sha256 = "0wb22hqkc4cyk2m3pj77r8khfimn3gh2dispw5sb4ay9blbmpj4j";
       goPackagePath = "golang.org/x/crypto";
       buildInputs = [
         net_crypto_lib
  
positive.code:       purgeTimestamps = true;
        inherit name;
        url = "https://code.googlesource.com/google-api-go-client/+archive/${rev}.tar.gz";
        sha256 = "03l87hva7fxw4grmvn32zhb44qgs3h513dvspdsqhkaxwqz3h5y8";
      };
      buildInputs = [
        appengine
  
negative.code:       procfs
        beorn7_perks
      ];
      date = "2017-06-06";
    };
  
    prometheus_client_model = buildFromGitHub {
  