(gdb) c
Continuing.

(gimp:3393): Gimp-Core-CRITICAL **: _gimp_unit_get_digits: assertion `unit < (GIMP_UNIT_END + gimp->n_user_units)' failed

Program received signal SIGTRAP, Trace/breakpoint trap.
0xb733069d in g_logv () from /lib/i386-linux-gnu/libglib-2.0.so.0
(gdb) bt
#0  0xb733069d in g_logv () from /lib/i386-linux-gnu/libglib-2.0.so.0
#1  0xb7330823 in g_log () from /lib/i386-linux-gnu/libglib-2.0.so.0
#2  0xb733086d in g_return_if_fail_warning ()
   from /lib/i386-linux-gnu/libglib-2.0.so.0
#3  0x0839ab9c in _gimp_unit_get_digits ()
#4  0x080b1298 in ?? ()
#5  0xb78a3d05 in gimp_unit_get_digits () from /usr/lib/libgimpbase-2.0.so.0
#6  0xb7ee1e80 in ?? () from /usr/lib/libgimpwidgets-2.0.so.0
#7  0xb7c51060 in gtk_tree_model_get_value ()
   from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#8  0xb53ce885 in ?? () from /usr/lib/i386-linux-gnu/gtk-2.0/modules/libgail.so
#9  0xb6fec8d6 in atk_object_get_name ()
   from /usr/lib/i386-linux-gnu/libatk-1.0.so.0
#10 0xb5d185e4 in ?? ()
   from /usr/lib/i386-linux-gnu/gtk-2.0/modules/libatk-bridge.so
#11 0xb5d18b8e in ?? ()
   from /usr/lib/i386-linux-gnu/gtk-2.0/modules/libatk-bridge.so
#12 0xb73ee690 in g_cclosure_marshal_VOID__OBJECTv ()
   from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#13 0xb73eb727 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#14 0xb7404a29 in g_signal_emit_valist ()
   from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#15 0xb7405453 in g_signal_emit ()
---Type <return> to continue, or q <return> to quit---
    <return>
   from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#16 0xb5d0e6c8 in ?? ()
   from /usr/lib/i386-linux-gnu/gtk-2.0/modules/libatk-bridge.so
#17 0xb7326850 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#18 0xb7328d86 in g_main_context_dispatch ()
   from /lib/i386-linux-gnu/libglib-2.0.so.0
#19 0xb7329125 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#20 0xb732956b in g_main_loop_run () from /lib/i386-linux-gnu/libglib-2.0.so.0
#21 0x080afb63 in app_run ()
#22 0x080af5d5 in main ()
(gdb) 
(script-fu:3401): LibGimpBase-WARNING **: script-fu: gimp_wire_read(): error

NB the last line above came when I foreced the closure of the frozen GIMP