Something

libtorrent::detail::write_endpoint<asio::ip::basic_endpoint<asio::ip::udp>, std::back_insert_iterator<std::string> > (e=@0x900b03c, out=@0xbfdde6f8)
    at ../include/libtorrent/asio/ip/basic_endpoint.hpp:255
255         if (is_v4())
(gdb) bt
#0  libtorrent::detail::write_endpoint<asio::ip::basic_endpoint<asio::ip::udp>, std::back_insert_iterator<std::string> > (e=@0x900b03c, out=@0xbfdde6f8)
    at ../include/libtorrent/asio/ip/basic_endpoint.hpp:255
#1  0xb7debb8e in libtorrent::dht::dht_tracker::state (this=0x85f7bc0) at kademlia/dht_tracker.cpp:654
#2  0xb7d3516c in libtorrent::aux::session_impl::dht_state (this=0x8443510) at session_impl.cpp:1543
#3  0xb7d3331c in libtorrent::session::dht_state (this=0x8442fc0) at session.cpp:230