Mac OSX running Carbon crash with today's CVS

[Gabriel Foster <gabriel@apple.com>]

Greetings,

	I'm gettting a random but fairly consistent crash on Mac OSX, built 
from today's CVS.  I'm using the Carbon UI.  Any ideas on a fix would 
be appreciated.  Here is the stack trace:

Program received signal EXC_BAD_ACCESS, Could not access memory.
0x000c48b4 in Fgarbage_collect () at alloc.c:4304
4304          XUNMARK (tail->var[i]);
(gdb) where
#0  0x000c48b4 in Fgarbage_collect () at alloc.c:4304
#1  0x00076540 in read_char (commandflag=1, nmaps=2, maps=0xbfffebd0, 
prev_event=275715796, used_mouse_menu=0xbfffecd4) at keyboard.c:2712
#2  0x0007e45c in read_key_sequence (keybuf=0xbfffeda0, 
bufsize=2373924, prompt=275715796, dont_downcase_last=2384204, 
can_return_switch_frame=1, fix_current_buffer=2371724) at 
keyboard.c:8583
#3  0x00073d5c in command_loop_1 () at keyboard.c:1502
#4  0x000d9cd4 in internal_condition_case (bfun=0x73918 
<command_loop_1>, handlers=275762388, hfun=0x732c8 <cmd_error>) at 
eval.c:1333
#5  0x000736f8 in command_loop_2 () at keyboard.c:1290
#6  0x000d9744 in internal_catch (tag=6348816, func=0x736b8 
<command_loop_2>, arg=275715796) at eval.c:1094
#7  0x00073650 in command_loop () at keyboard.c:1269
#8  0x00073064 in recursive_edit_1 () at keyboard.c:985
#9  0x000731ec in Frecursive_edit () at keyboard.c:1041
#10 0x00071cc0 in main (argc=0, argv=0xbffffa44) at emacs.c:1659
#11 0x00003ae8 in _start (argc=50, argv=0x0, envp=0x2405b4) at 
/SourceCache/Csu/Csu-45/crt.c:267
#12 0x00003968 in start ()
(gdb) list
4299
4300    #if (GC_MARK_STACK == GC_USE_GCPROS_AS_BEFORE \
4301         || GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES)
4302      for (tail = gcprolist; tail; tail = tail->next)
4303        for (i = 0; i < tail->nvars; i++)
4304          XUNMARK (tail->var[i]);
4305    #endif
4306
4307      unmark_byte_stack ();
4308      for (backlist = backtrace_list; backlist; backlist = 
backlist->next)
(gdb) print tail
$1 = (struct gcpro *) 0xbfffde90
(gdb) print tail->nvars
$2 = 1168308
(gdb) print i
$3 = 7289
(gdb)

Mac OS 10.2.5

emacs --version
GNU Emacs 21.3.50.2
Copyright (C) 2002 Free Software Foundation, Inc.