Obtained 22 stack frames.
/usr/games/crawl-git-43d89d912d(_Z17write_stack_traceP8_IO_FILE+0x3f) [0x6153cdf634ef]: write_stack_trace(_IO_FILE*)
/usr/games/crawl-git-43d89d912d(_Z20crash_signal_handleri+0x196) [0x6153cdf63986]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x75f008d1a330]: 
/usr/games/crawl-git-43d89d912d(_Z12dgn_vault_at9coord_def+0x42) [0x6153ce0290a2]: dgn_vault_at(coord_def)
/usr/games/crawl-git-43d89d912d(_Z23raw_feature_descriptionB5cxx11RK9coord_def+0x55) [0x6153ce009065]: raw_feature_description[abi:cxx11](coord_def const&)
/usr/games/crawl-git-43d89d912d(_Z13do_crash_dumpv+0x2237) [0x6153cdf73577]: do_crash_dump()
/usr/games/crawl-git-43d89d912d(_Z20crash_signal_handleri+0x1fa) [0x6153cdf639ea]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x45330) [0x75f008d1a330]: 
/lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x11c) [0x75f008d73b2c]: 
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x1e) [0x75f008d1a27e]: 
/usr/games/crawl-git-43d89d912d(+0x562b4d) [0x6153cdf70b4d]: 
/usr/games/crawl-git-43d89d912d(_Z12AssertFailedPKcS0_iS0_z+0x1c7) [0x6153cdf71057]: AssertFailed(char const*, char const*, int, char const*, ...)
/usr/games/crawl-git-43d89d912d(_Z9save_gamebPKc+0x7c4) [0x6153ce07eb14]: save_game(bool, char const*)
/usr/games/crawl-git-43d89d912d(_Z21check_selected_skillsv+0x257) [0x6153ce52e527]: check_selected_skills()
/usr/games/crawl-git-43d89d912d(+0x66ef65) [0x6153ce07cf65]: 
/usr/games/crawl-git-43d89d912d(_Z12restore_gameRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x23) [0x6153ce07da93]: restore_game(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
/usr/games/crawl-git-43d89d912d(_Z12startup_stepv+0x947) [0x6153ce5cb0c7]: startup_step()
/usr/games/crawl-git-43d89d912d(+0xd4ce1d) [0x6153ce75ae1d]: 
/usr/games/crawl-git-43d89d912d(main+0x1f7) [0x6153cde91d27]: 
/lib/x86_64-linux-gnu/libc.so.6(+0x2a1ca) [0x75f008cff1ca]: 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x8b) [0x75f008cff28b]: 
/usr/games/crawl-git-43d89d912d(_start+0x25) [0x6153cde92815]: