set_backtrace    3614 eval.c         	    set_backtrace(mesg, at);
set_backtrace    3705 eval.c         	set_backtrace(mesg, (argc>2)?argv[2]:Qnil);
set_backtrace    5925 eval.c             set_backtrace(ruby_errinfo, val);
set_backtrace    8260 eval.c         	set_backtrace(th->errinfo, errat);