Obtained 22 stack frames.
/usr/games/crawl-0.34(_Z17write_stack_traceP8_IO_FILE+0x3e) [0x5aebcb945e0e]: write_stack_trace(_IO_FILE*)
/usr/games/crawl-0.34(_Z20crash_signal_handleri+0x18f) [0x5aebcb94627f]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x7fee846a7330]: 
/usr/games/crawl-0.34(_Z12dgn_vault_at9coord_def+0x42) [0x5aebcba06ca2]: dgn_vault_at(coord_def)
/usr/games/crawl-0.34(_Z23raw_feature_descriptionB5cxx11RK9coord_def+0x5c) [0x5aebcb9e761c]: raw_feature_description[abi:cxx11](coord_def const&)
/usr/games/crawl-0.34(_Z13do_crash_dumpv+0x227a) [0x5aebcb955eaa]: do_crash_dump()
/usr/games/crawl-0.34(_Z20crash_signal_handleri+0x1fa) [0x5aebcb9462ea]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x7fee846a7330]: 
/lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x11c) [0x7fee84700b2c]: 
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x1e) [0x7fee846a727e]: 
/usr/games/crawl-0.34(+0x50343d) [0x5aebcb95343d]: 
/usr/games/crawl-0.34(_Z12AssertFailedPKcS0_iS0_z+0x1c7) [0x5aebcb953947]: AssertFailed(char const*, char const*, int, char const*, ...)
/usr/games/crawl-0.34(_Z9save_gamebPKc+0x7c4) [0x5aebcba5a5d4]: save_game(bool, char const*)
/usr/games/crawl-0.34(_Z21check_selected_skillsv+0x257) [0x5aebcbef8187]: check_selected_skills()
/usr/games/crawl-0.34(+0x608afc) [0x5aebcba58afc]: 
/usr/games/crawl-0.34(_Z12restore_gameRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x23) [0x5aebcba59553]: restore_game(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
/usr/games/crawl-0.34(_Z12startup_stepv+0x947) [0x5aebcbf8f167]: startup_step()
/usr/games/crawl-0.34(+0xcc3aed) [0x5aebcc113aed]: 
/usr/games/crawl-0.34(main+0x1f7) [0x5aebcb877907]: 
/lib/x86_64-linux-gnu/libc.so.6(+0x2a1ca) [0x7fee8468c1ca]: 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x8b) [0x7fee8468c28b]: 
/usr/games/crawl-0.34(_start+0x25) [0x5aebcb8783f5]: