次のようにすると core を吐きます

% ./ruby -e '
def m(&block)
  lambda {
    class << Object.new; self end.__send__(:define_method, :zzz, &block)
  }
end

v = eval("m {}")
p 1
v.call
'
1
-e:4: [BUG] Segmentation fault
ruby 1.9.0 (2004-09-06) [i686-linux]

zsh: abort (core dumped)  ./ruby -e 
% gdb ruby core 
GNU gdb 6.1-debian
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-linux"...Using host libthread_db library "/lib/libthread_db.so.1".

Core was generated by `./ruby -e 
def m(&block)
  lambda { 
    class << Object.new; self end.__send__'.
Program terminated with signal 6, Aborted.
Reading symbols from /lib/libdl.so.2...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /lib/libcrypt.so.1...done.
Loaded symbols for /lib/libcrypt.so.1
Reading symbols from /lib/libm.so.6...done.
Loaded symbols for /lib/libm.so.6
Reading symbols from /lib/libc.so.6...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
#0  0x4009d721 in kill () from /lib/libc.so.6
(gdb) bt
#0  0x4009d721 in kill () from /lib/libc.so.6
#1  0x4009d4c5 in raise () from /lib/libc.so.6
#2  0x4009e9e8 in abort () from /lib/libc.so.6
#3  0x080d0b26 in rb_bug (fmt=0x0) at error.c:214
#4  0x080af152 in sigsegv (sig=11) at signal.c:446
#5  <signal handler called>
#6  0x080623d5 in frame_dup (frame=0x8139180) at eval.c:7774
#7  0x080628df in proc_alloc (klass=135499820, proc=2) at eval.c:7940
#8  0x08062aec in proc_lambda () at eval.c:8020
#9  0x08064954 in rb_mod_define_method (argc=135500208, argv=0xbfffdd9c, mod=1075603820) at eval.c:9126
#10 0x08069e7a in call_cfunc (func=0x8064780 <rb_mod_define_method>, recv=1075603820, len=135500248, argc=11, 
    argv=0xbfffdd9c) at eval.c:5364
#11 0x0805e117 in rb_call0 (klass=1075674380, recv=1075603820, id=4217, oid=135500208, argc=1, argv=0xbfffdd9c, 
    body=0x401d5994, nosuper=0) at eval.c:5504
#12 0x0805e3c8 in rb_call (klass=1075674380, recv=1075603820, mid=4217, argc=1, argv=0xbfffdd9c, scope=1) at eval.c:5725
#13 0x0805e634 in rb_f_send (argc=1, argv=0xbfffdd9c, recv=1075603820) at ruby.h:634
#14 0x08069e7a in call_cfunc (func=0x805e5b0 <rb_f_send>, recv=1075603820, len=135500248, argc=11, argv=0xbfffdd98)
    at eval.c:5364
#15 0x0805e117 in rb_call0 (klass=1075674280, recv=1075603820, id=3929, oid=135500208, argc=2, argv=0xbfffdd98, 
    body=0x401d5cc8, nosuper=0) at eval.c:5504
#16 0x0805e3c8 in rb_call (klass=1075674280, recv=1075603820, mid=3929, argc=2, argv=0xbfffdd98, scope=0) at eval.c:5725
#17 0x08059308 in rb_eval (self=1075669400, n=0x81391b0) at ruby.h:634
#18 0x08063710 in block_pass (self=1075669400, node=0x401c6cb4) at eval.c:8401
#19 0x08059ee7 in rb_eval (self=1075669400, n=0x81391b0) at eval.c:2906
#20 0x0805c1a3 in rb_yield_0 (val=1075603880, self=1075669400, klass=1075604660, flags=3, avalue=2) at eval.c:4705
#21 0x08062e7f in proc_invoke (proc=1075603920, args=1075603880, self=6, klass=0) at ruby.h:634
#22 0x08062f17 in proc_call (proc=135500208, args=135500208) at eval.c:8154
#23 0x08069e52 in call_cfunc (func=0x8062ef0 <proc_call>, recv=1075603920, len=135500248, argc=11, argv=0x0) at eval.c:5361
#24 0x0805e117 in rb_call0 (klass=1075610420, recv=1075603920, id=5265, oid=135500208, argc=0, argv=0x0, body=0x401c82a8, 
    nosuper=0) at eval.c:5504
#25 0x0805e3c8 in rb_call (klass=1075610420, recv=1075603920, mid=5265, argc=0, argv=0x0, scope=0) at eval.c:5725
#26 0x08059308 in rb_eval (self=1075669400, n=0x81391b0) at ruby.h:634
#27 0x0805589b in ruby_exec () at eval.c:1458
#28 0x080558e0 in ruby_run () at eval.c:1479
#29 0x080539b5 in main (argc=135500208, argv=0x81391b0, envp=0xbffff914) at main.c:38
(gdb) 
-- 
[田中 哲][たなか あきら][Tanaka Akira]