anchor.diff: -{ lib, stdenv, fetchFromGitHub
  +{ lib, stdenv, fetchFromGitHub, darwin
   , cmake, pkg-config
   , asio, nettle, gnutls, msgpack, readline, libargon2
   }:
  
positive.code:       msgpack
        readline
        libargon2
      ];
  
    outputs = [ "out" "lib" "dev" "man" ];
  
negative.code:     homepage    = "https://github.com/savoirfairelinux/opendht";
      license     = licenses.gpl3Plus;
      maintainers = with maintainers; [ taeer olynch thoughtpolice ];
      platforms   = platforms.unix;
    };
  }
  