こんばんは、sheepman です。
次のようにすると core を吐きます。

$ ./miniruby -e 'at_exit{break}'
-e:1: unexpected break
zsh: segmentation fault (core dumped)  ./miniruby -e 'at_exit{break}'

$ gdb miniruby core.11144
#0  rb_bug (fmt=0x80f176d "Segmentation fault") at ../yarv/error.c:161
161       int len = err_position(buf, BUFSIZ);
(gdb) bt
#0  rb_bug (fmt=0x80f176d "Segmentation fault") at ../yarv/error.c:161
#1  0x080a0f4f in sigsegv (sig=11) at ../yarv/signal.c:503
#2  0x4002ce8e in __pthread_clock_settime () from /lib/i686/libpthread.so.0
#3  0x400ec908 in killpg () from /lib/i686/libc.so.6
#4  0x080c821b in rb_bug (fmt=0x80f176d "Segmentation fault") at ../yarv/error.c:161
#5  0x080a0f4f in sigsegv (sig=11) at ../yarv/signal.c:503
#6  0x4002ce8e in __pthread_clock_settime () from /lib/i686/libpthread.so.0
#7  0x400ec908 in killpg () from /lib/i686/libc.so.6
#8  0x080c821b in rb_bug (fmt=0x80f176d "Segmentation fault") at ../yarv/error.c:161
#9  0x080a0f4f in sigsegv (sig=11) at ../yarv/signal.c:503
#10 0x4002ce8e in __pthread_clock_settime () from /lib/i686/libpthread.so.0
#11 0x400ec908 in killpg () from /lib/i686/libc.so.6
#12 0x080c821b in rb_bug (fmt=0x80f176d "Segmentation fault") at ../yarv/error.c:161
#13 0x080a0f4f in sigsegv (sig=11) at ../yarv/signal.c:503
#14 0x4002ce8e in __pthread_clock_settime () from /lib/i686/libpthread.so.0
#15 0x400ec908 in killpg () from /lib/i686/libc.so.6
........
#3581 0x080a0f4f in sigsegv (sig=11) at ../yarv/signal.c:503
#3582 0x4002ce8e in __pthread_clock_settime () from /lib/i686/libpthread.so.0
#3583 0x400ec908 in killpg () from /lib/i686/libc.so.6
#3584 0x080c821b in rb_bug (fmt=Cannot access memory at address 0xbffe7da0
) at ../yarv/error.c:161
Cannot access memory at address 0xbffe7d98

-- 
sheepman / TAMURA Takashi
sheepman sheepman.sakura.ne.jp http://sheepman.parfait.ne.jp/
   

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