HAVE_BACKTRACE    379 .ext/include/x86_64-linux/ruby/config.h #define HAVE_BACKTRACE 1
HAVE_BACKTRACE    497 vm_dump.c      #  undef HAVE_BACKTRACE
HAVE_BACKTRACE    498 vm_dump.c      #  define HAVE_BACKTRACE 0
HAVE_BACKTRACE    501 vm_dump.c      # define HAVE_BACKTRACE 0