Segmentation fault on Struct

[ksss]

This code failed.

Struct.new(:foo) {
  def initialize(*)
    self.foo
  end
}.new

$ lldb mruby t.rb
(lldb) target create "mruby"
Current executable set to 'mruby' (x86_64).
(lldb) settings set -- target.run-args  "t.rb"
(lldb) r
Process 52549 launched: '/Users/yuki/bin/mruby' (x86_64)
Process 52549 stopped
* thread #1: tid = 0xcfdafb, 0x0000000100050527 mruby`mrb_struct_ref0(mrb=0x00000001002029f0, obj=mrb_value @ 0x00007fff5fbfd700) + 23 at struct.c:128, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
    frame #0: 0x0000000100050527 mruby`mrb_struct_ref0(mrb=0x00000001002029f0, obj=mrb_value @ 0x00007fff5fbfd700) + 23 at struct.c:128
   125    return mrb_struct_getmember(mrb, obj, mrb->c->ci->mid);
   126  }
   127
-> 128  static mrb_value mrb_struct_ref0(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[0];}
   129  static mrb_value mrb_struct_ref1(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[1];}
   130  static mrb_value mrb_struct_ref2(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[2];}
   131  static mrb_value mrb_struct_ref3(mrb_state* mrb, mrb_value obj) {return RSTRUCT_PTR(obj)[3];}