anchor.diff:        purgeTimestamps = true;
         inherit name;
         url = "https://code.googlesource.com/google-api-go-client/+archive/${rev}.tar.gz";
  -      sha256 = "1y0lsgx44v125y7004qi8ra66rr46yncjdqmmq9nj164i4ji8lfn";
  +      sha256 = "1csxhgm0wpb1wd5x5jhcpqgllpsl3v14ix07fjm9ai4fc5irq7c2";
       };
       buildInputs = [
         appengine
  
positive.code:     version = 5;
      owner = "census-instrumentation";
      repo = "opencensus-go";
      rev = "348c330238ab59f3265db2fed041680a94099f20";
      sha256 = "1var01xahqk53bzs5gyqyjfjs3zxfrkmfv2cwwlyk2vsfhy4g2fq";
      goPackagePath = "go.opencensus.io";
      subPackages = [
        "internal/tagencoding"
        "plugin/grpc"
        "plugin/grpc/grpcstats"
  
negative.code: 
    macaroon-bakery_v2 = buildFromGitHub {
      version = 5;
      rev = "22c04a94d902625448265ef041bb53e715452a40";
      owner  = "go-macaroon-bakery";
      repo   = "macaroon-bakery";
      sha256 = "1422911sxqmps8vzmh14rkxj16q9f5xwxyagzz7kbdlhk06lqq57";
      goPackagePath = "gopkg.in/macaroon-bakery.v2";
      date = "2018-02-09";
      excludedPackages = "\\(test\\|example\\)";
      propagatedBuildInputs = [
        crypto
  