Obtained 20 stack frames.
/usr/games/crawl-git-2d68f2b6bc(_Z17write_stack_traceP8_IO_FILE+0x3e) [0x58e2e2e90e9e]: write_stack_trace(_IO_FILE*)
/usr/games/crawl-git-2d68f2b6bc(_Z20crash_signal_handleri+0x18f) [0x58e2e2e9130f]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x42910) [0x706414042910]: 
/lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x11b) [0x70641409999b]: 
/lib/x86_64-linux-gnu/libc.so.6(raise+0x16) [0x706414042866]: 
/usr/games/crawl-git-2d68f2b6bc(+0x4ef45d) [0x58e2e2e9e45d]: 
/usr/games/crawl-git-2d68f2b6bc(_Z10die_nolinePKcz+0x16b) [0x58e2e2e9ec4b]: die_noline(char const*, ...)
/usr/games/crawl-git-2d68f2b6bc(_Z20crash_signal_handleri+0x2d0) [0x58e2e2e91450]: crash_signal_handler(int)
/lib/x86_64-linux-gnu/libc.so.6(+0x42910) [0x706414042910]: 
/usr/games/crawl-git-2d68f2b6bc(_Z13cell_see_cellRK9coord_defS1_8los_type+0x13f) [0x58e2e316e84f]: cell_see_cell(coord_def const&, coord_def const&, los_type)
/usr/games/crawl-git-2d68f2b6bc(_ZN15vision_iteratorppEv+0x68) [0x58e2e2e8f708]: vision_iterator::operator++()
/usr/games/crawl-git-2d68f2b6bc(_Z9show_init13enum_bitfieldI5LayerLi5EE+0x8f) [0x58e2e34170ff]: show_init(enum_bitfield<Layer, 5>)
/usr/games/crawl-git-2d68f2b6bc(_Z10viewwindowbbP9animationP13view_renderer+0x140) [0x58e2e3592440]: viewwindow(bool, bool, animation*, view_renderer*)
/usr/games/crawl-git-2d68f2b6bc(+0xc9038c) [0x58e2e363f38c]: 
/usr/games/crawl-git-2d68f2b6bc(+0xc928f6) [0x58e2e36418f6]: 
/usr/games/crawl-git-2d68f2b6bc(+0xc93a05) [0x58e2e3642a05]: 
/usr/games/crawl-git-2d68f2b6bc(main+0x1f7) [0x58e2e2dc5287]: 
/lib/x86_64-linux-gnu/libc.so.6(+0x280d0) [0x7064140280d0]: 
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x89) [0x706414028189]: 
/usr/games/crawl-git-2d68f2b6bc(_start+0x25) [0x58e2e2dc5d75]: