anchor.diff:        seed
       ];
       meta.useUnstable = true;
  -    date = "2017-07-17";
  +    date = "2017-08-07";
     };
   
     memcache = buildFromGitHub {
  
positive.code: 
    swarmkit = buildFromGitHub {
      version = 3;
      rev = "975a197fd256322c42cdbec05a9d4eb16d8d18f2";
      owner = "docker";
      repo = "swarmkit";
      sha256 = "0f6qy3lfqbwd4d3g28lmfywhcbxpwf7d47q2c9dn5y3590pnhfx5";
      date = "2017-08-02";
      subPackages = [
        "api"
        "api/deepcopy"
  
negative.code: 
    mitchellh_cli = buildFromGitHub {
      version = 3;
      date = "2017-08-03";
      rev = "8a539dbef410aa4191e0bcc7a6246c104b313009";
      owner = "mitchellh";
      repo = "cli";
      sha256 = "16l4d1ab6vq7vq11pyihzp3q0wrdq3mlh3hvmyg6xaz3j5xk284j";
      propagatedBuildInputs = [
        complete
        crypto
  