Obtained 22 stack frames.
/usr/games/crawl-0.34(_Z17write_stack_traceP8_IO_FILE+0x3e) [0x5b24b5cdf95e]: write_stack_trace(_IO_FILE*)
/usr/games/crawl-0.34(_Z20crash_signal_handleri+0x18f) [0x5b24b5cdfdcf]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x42910) [0x7119f6a42910]: 
/usr/games/crawl-0.34(_Z12dgn_vault_at9coord_def+0x42) [0x5b24b5da0902]: dgn_vault_at(coord_def)
/usr/games/crawl-0.34(_Z23raw_feature_descriptionB5cxx11RK9coord_def+0x5c) [0x5b24b5d80fbc]: raw_feature_description[abi:cxx11](coord_def const&)
/usr/games/crawl-0.34(_Z13do_crash_dumpv+0x228a) [0x5b24b5cef9ea]: do_crash_dump()
/usr/games/crawl-0.34(_Z20crash_signal_handleri+0x1fa) [0x5b24b5cdfe3a]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x42910) [0x7119f6a42910]: 
/lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x11b) [0x7119f6a9999b]: 
/lib/x86_64-linux-gnu/libc.so.6(raise+0x16) [0x7119f6a42866]: 
/usr/games/crawl-0.34(+0x501f6d) [0x5b24b5cecf6d]: 
/usr/games/crawl-0.34(_Z12AssertFailedPKcS0_iS0_z+0x1c7) [0x5b24b5ced477]: AssertFailed(char const*, char const*, int, char const*, ...)
/usr/games/crawl-0.34(_Z9save_gamebPKc+0x7c4) [0x5b24b5df39b4]: save_game(bool, char const*)
/usr/games/crawl-0.34(_Z21check_selected_skillsv+0x257) [0x5b24b628f087]: check_selected_skills()
/usr/games/crawl-0.34(+0x606da8) [0x5b24b5df1da8]: 
/usr/games/crawl-0.34(_Z12restore_gameRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x23) [0x5b24b5df2933]: restore_game(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
/usr/games/crawl-0.34(_Z12startup_stepv+0x947) [0x5b24b6325f07]: startup_step()
/usr/games/crawl-0.34(+0xcbf62d) [0x5b24b64aa62d]: 
/usr/games/crawl-0.34(main+0x1f7) [0x5b24b5c113b7]: 
/lib/x86_64-linux-gnu/libc.so.6(+0x280d0) [0x7119f6a280d0]: 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x89) [0x7119f6a28189]: 
/usr/games/crawl-0.34(_start+0x25) [0x5b24b5c11ea5]: