gauss:rubinius brian$ gdb --args vm/vm -Xint --melbourne  mspec/bin/mspec-ci --ast -B full
GNU gdb 6.3.50-20050815 (Apple version gdb-966) (Tue Mar 10 02:43:13 UTC 2009)
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This GDB was configured as "i386-apple-darwin"...Reading symbols for shared libraries ..... done

(gdb) r
Starting program: /Users/brian/devel/rubinius/vm/vm -Xint --melbourne mspec/bin/mspec-ci --ast -B full
Reading symbols for shared libraries ++++. done
Reading symbols for shared libraries . done
...................................................................................................................................................................................................................
Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x2f737568
0x00050727 in rubinius::ObjectHeader::forwarded_p (this=0x13984d8) at oop.hpp:365
365           return flags().Forwarded == 1;
(gdb) in thr
Ambiguous command "in thr": info, inspect, internals, interpreter-exec, interrupt.
(gdb) info thr
Ambiguous info command "thr": thread, threads.
(gdb) info thread
Thread 0x813 (local 0x2e03) has current state "WAITING"
Thread 0x813 has a suspend count of 0.
(gdb) info threads
  3 process 23116 thread 0x1003  0x955ce46e in __semwait_signal ()
  2 process 23116 thread 0x313  0x955ce46e in __semwait_signal ()
* 1 process 23116 local thread 0x2e03  0x00050727 in rubinius::ObjectHeader::forwarded_p (this=0x13984d8) at oop.hpp:365
(gdb) info thread 2
Thread 0x313 (local 0x3503) has current state "WAITING"
Thread 0x313 has a suspend count of 0.
(gdb) info thread 3
Thread 0x1003 (local 0x3603) has current state "WAITING"
Thread 0x1003 has a suspend count of 0.
(gdb) bt 5
#0  0x00050727 in rubinius::ObjectHeader::forwarded_p (this=0x13984d8) at oop.hpp:365
#1  0x00154aee in rubinius::BakerGC::find_lost_souls (this=0x1110b70) at vm/gc/baker.cpp:298
#2  0x001552ff in rubinius::BakerGC::collect (this=0x1110b70, data=@0xbfff02dc, stats=0xbfff02c4) at vm/gc/baker.cpp:209
#3  0x00067d50 in rubinius::ObjectMemory::collect_young (this=0x1110a60, data=@0xbfff02dc, stats=0xbfff02c4) at vm/objectmemory.cpp:131
#4  0x000fa8e8 in rubinius::VM::collect_maybe (this=0x1100e80, call_frame=0xbfff0aa0) at vm/vm.cpp:276
(More stack frames follow...)
(gdb) l
365           return flags().Forwarded == 1;
366         }
367
368         void clear_forwarded() {
369           flags().Forwarded = 0;
370         }
371
372         Object* forward() {
373           return ivars_;
374         }
(gdb) fr 1
#1  0x00154aee in rubinius::BakerGC::find_lost_souls (this=0x1110b70) at vm/gc/baker.cpp:298
298           if(!obj->forwarded_p()) {
(gdb) l
293           obj = next_object(obj);
294         }
295
296         obj = eden.first_object();
297         while(obj < eden.current()) {
298           if(!obj->forwarded_p()) {
299     #ifdef RBX_GC_STATS
300             stats::GCStats::get()->lifetimes[obj->age()]++;
301     #endif
302           }
(gdb) p obj
$1 = (class rubinius::Object *) 0x13984d8
(gdb) p eden
$2 = {
  start_ = 0x1300000,
  current_ = 0x15ffa18,
  last_ = 0x15fffff,
  scan_ = 0x1300000,
  limit_ = 0x15ff3b6,
  size_ = 3145728
}
(gdb) p eden.first_object()
$3 = (class rubinius::Object *) 0x1300000
(gdb) p eden.current() - eden.last_object()
Couldn't find method rubinius::Heap::last_object
(gdb) p 0x15ffa18 - 0x15fffff
$4 = -1511
(gdb) p 0x15ffa18 - 0x13984d8
$5 = 2520384
(gdb) p *obj
$6 = {
  <rubinius::ObjectHeader> = {
    header = {
      f = {
        inflated = 1,
        obj_type = 180,
        zone = rubinius::MatureObjectZone,
        age = 14,
        Forwarded = 0,
        Remember = 1,
        Marked = 1,
        RequiresCleanup = 0,
        InImmix = 1,
        Pinned = 1
      },
      all_flags = 0x2f737569
    },
    klass_ = 0x63657073,
    ivars_ = 0x6f72662f,
    __body__ = 0x13984e4
  },
  members of rubinius::Object:
  static type = <optimized out>
}