Obtained 22 stack frames.
/usr/games/crawl-git-54e886eacc(_Z17write_stack_traceP8_IO_FILE+0x3f) [0x57a2d53543ff]: write_stack_trace(_IO_FILE*)
/usr/games/crawl-git-54e886eacc(_Z20crash_signal_handleri+0x196) [0x57a2d5354896]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x7adebd3c6330]: 
/usr/games/crawl-git-54e886eacc(_Z12dgn_vault_at9coord_def+0x42) [0x57a2d5419672]: dgn_vault_at(coord_def)
/usr/games/crawl-git-54e886eacc(_Z23raw_feature_descriptionB5cxx11RK9coord_def+0x55) [0x57a2d53f9645]: raw_feature_description[abi:cxx11](coord_def const&)
/usr/games/crawl-git-54e886eacc(_Z13do_crash_dumpv+0x2237) [0x57a2d5364457]: do_crash_dump()
/usr/games/crawl-git-54e886eacc(_Z20crash_signal_handleri+0x1fa) [0x57a2d53548fa]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x7adebd3c6330]: 
/lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x11c) [0x7adebd41fb2c]: 
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x1e) [0x7adebd3c627e]: 
/usr/games/crawl-git-54e886eacc(+0x552a2d) [0x57a2d5361a2d]: 
/usr/games/crawl-git-54e886eacc(_Z12AssertFailedPKcS0_iS0_z+0x1c7) [0x57a2d5361f37]: AssertFailed(char const*, char const*, int, char const*, ...)
/usr/games/crawl-git-54e886eacc(_Z9save_gamebPKc+0x7c4) [0x57a2d546e9c4]: save_game(bool, char const*)
/usr/games/crawl-git-54e886eacc(_Z21check_selected_skillsv+0x257) [0x57a2d5916ce7]: check_selected_skills()
/usr/games/crawl-git-54e886eacc(+0x65de15) [0x57a2d546ce15]: 
/usr/games/crawl-git-54e886eacc(_Z12restore_gameRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x23) [0x57a2d546d943]: restore_game(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
/usr/games/crawl-git-54e886eacc(_Z12startup_stepv+0x937) [0x57a2d59b0847]: startup_step()
/usr/games/crawl-git-54e886eacc(+0xd2d17d) [0x57a2d5b3c17d]: 
/usr/games/crawl-git-54e886eacc(main+0x1f7) [0x57a2d52860b7]: 
/lib/x86_64-linux-gnu/libc.so.6(+0x2a1ca) [0x7adebd3ab1ca]: 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x8b) [0x7adebd3ab28b]: 
/usr/games/crawl-git-54e886eacc(_start+0x25) [0x57a2d5286ba5]: