Obtained 22 stack frames.
/usr/games/crawl-0.34(_Z17write_stack_traceP8_IO_FILE+0x3e) [0x623d4d353e0e]: write_stack_trace(_IO_FILE*)
/usr/games/crawl-0.34(_Z20crash_signal_handleri+0x18f) [0x623d4d35427f]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x737da1335330]: 
/usr/games/crawl-0.34(_Z12dgn_vault_at9coord_def+0x42) [0x623d4d414ca2]: dgn_vault_at(coord_def)
/usr/games/crawl-0.34(_Z23raw_feature_descriptionB5cxx11RK9coord_def+0x5c) [0x623d4d3f561c]: raw_feature_description[abi:cxx11](coord_def const&)
/usr/games/crawl-0.34(_Z13do_crash_dumpv+0x227a) [0x623d4d363eaa]: do_crash_dump()
/usr/games/crawl-0.34(_Z20crash_signal_handleri+0x1fa) [0x623d4d3542ea]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x737da1335330]: 
/lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x11c) [0x737da138eb2c]: 
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x1e) [0x737da133527e]: 
/usr/games/crawl-0.34(+0x50343d) [0x623d4d36143d]: 
/usr/games/crawl-0.34(_Z12AssertFailedPKcS0_iS0_z+0x1c7) [0x623d4d361947]: AssertFailed(char const*, char const*, int, char const*, ...)
/usr/games/crawl-0.34(_Z9save_gamebPKc+0x7c4) [0x623d4d4685d4]: save_game(bool, char const*)
/usr/games/crawl-0.34(_Z21check_selected_skillsv+0x257) [0x623d4d906187]: check_selected_skills()
/usr/games/crawl-0.34(+0x608afc) [0x623d4d466afc]: 
/usr/games/crawl-0.34(_Z12restore_gameRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x23) [0x623d4d467553]: restore_game(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
/usr/games/crawl-0.34(_Z12startup_stepv+0x947) [0x623d4d99d167]: startup_step()
/usr/games/crawl-0.34(+0xcc3aed) [0x623d4db21aed]: 
/usr/games/crawl-0.34(main+0x1f7) [0x623d4d285907]: 
/lib/x86_64-linux-gnu/libc.so.6(+0x2a1ca) [0x737da131a1ca]: 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x8b) [0x737da131a28b]: 
/usr/games/crawl-0.34(_start+0x25) [0x623d4d2863f5]: