anchor.diff:  
     go-ethereum = buildFromGitHub {
       version = 2;
  -    date = "2017-03-16";
  -    rev = "6d038e762b2ff5785d6884f09f869c45964647aa";
  +    date = "2017-03-20";
  +    rev = "1dfd65f6d047407585845dfe9be2ff52a8b9f3ab";
       owner  = "ethereum";
       repo   = "go-ethereum";
  -    sha256 = "0ix3ba9m8awfyjg5pik72k5qxjcvg3j0nwcsnllz3f60vjv8rl2f";
  +    sha256 = "18yw5ymj939rh8ambjps3jvarav5nzclw0544kaa1jbhgvshgwwk";
       subPackages = [
         "crypto/sha3"
       ];
  
positive.code:       profile
        structs
      ];
      date = "2017-03-14";
    };
  
    mdns = buildFromGitHub {
  
negative.code: 
    ledisdb = buildFromGitHub {
      version = 2;
      rev = "5929802e2ea51f20e4ebb4076a8be2c899094e56";
      owner  = "siddontang";
      repo   = "ledisdb";
      sha256 = "0hvq1333sgy4ylivpw72h27fjdag1hqaybp078qpkkjjjimcf04v";
      date = "2017-03-18";
      prePatch = ''
        dirs=($(find . -type d -name vendor | sort))
        echo "''${dirs[@]}" | xargs -n 1 rm -r
  