(gdb) source /Users/dr/workspace/emacs/src/.gdbinit
Warning: /Users/dr/workspace/emacs/../lwlib: No such file or directory.
SIGINT is used by the debugger.
Are you sure you want to change it? (y or n) [answered Y; input not from
terminal]
Redefine command "xgetptr"? (y or n) [answered Y; input not from terminal]
...
TERM = xterm-256color
Breakpoint 8 at 0x10017a032: file emacs.c, line 354.
Temporary breakpoint 9 at 0x1001b648f: file sysdep.c, line 915.
(gdb) frame 10437
#10437 0x00000001000393d4 in get_next_display_element (it=0x7fff5fbd5bb0)
    at xdisp.c:7324
warning: Source file is more recent than executable.
7324      success_p = get_next_display_element (it);
(gdb) p it->current
$7 = {
  pos = {
    charpos = 4138,
    bytepos = 4138
  },
  overlay_string_index = -1,
  string_pos = {
    charpos = 6,
    bytepos = 6
  },
  dpvec_index = -1
}
(gdb) p it->sp
$8 = 2
(gdb) p it->object
$9 = Python Exception <type 'exceptions.AttributeError'> 'NoneType' object
has no attribute 'value':

(gdb) xtype
Lisp_String
(gdb) p it->position
$10 = {
  charpos = 0,
  bytepos = 0
}
(gdb)  p it->string
$11 = Python Exception <type 'exceptions.AttributeError'> 'NoneType' object
has no attribute 'value':

(gdb) xstring
$12 = (struct Lisp_String *) 0x10da1ee10
" 163"