anchor.diff:  
     crypto = buildFromGitHub {
       version = 2;
  -    rev = "459e26527287adbc2adcc5d0d49abff9a5f315a7";
  -    date = "2017-03-17";
  +    rev = "3cb07270c9455e8ad27956a70891c962d121a228";
  +    date = "2017-03-30";
       owner    = "golang";
       repo     = "crypto";
  -    sha256 = "0mf5zfcx3rr565m9ip4fqz4lzsr75jsh3b5awd39xxinz8453vyj";
  +    sha256 = "0ilpqn2silqmdmj37amilgqd9gdg0sy7nw2vfp3918pd41g368ys";
       goPackagePath = "golang.org/x/crypto";
       goPackageAliases = [
         "code.google.com/p/go.crypto"
  
positive.code:     version = 2;
      owner = "xtaci";
      repo = "kcp-go";
      rev = "v3.11";
      sha256 = "118nmy61ah6mh0zyz9l1652n4w0vx73fp26gjqlr5c0w5xrizh78";
      propagatedBuildInputs = [
        crypto
        errors
  
negative.code:       net
        vultr
      ];
      date = "2017-03-30";
    };
  
    lemma = buildFromGitHub {
  