(gdb) bt
#0  Interp::store_named_param (this=0x10d45e10, settings=0x10d46618,
    nameBuf=0x0, value=0, override_readonly=0)
    at emc/rs274ngc/interp_namedparams.cc:411
#1  0x01054aad in Interp::_execute (this=0x10d45e10, command=0x0)
    at emc/rs274ngc/rs274ngc_pre.cc:347
#2  0x01054fb0 in Interp::execute (this=0x10d45e10, command=0x0)
    at emc/rs274ngc/rs274ngc_pre.cc:509
#3  0x01055000 in Interp::execute (this=0x10d45e10)
    at emc/rs274ngc/rs274ngc_pre.cc:517
#4  0x0029a755 in parse_file (self=0x0, args=0x1148b0bc)
    at emc/rs274ngc/gcodemodule.cc:723
#5  0x080e114f in PyEval_EvalFrameEx ()
#6  0x080e2977 in PyEval_EvalCodeEx ()
#7  0x080e0fb3 in PyEval_EvalFrameEx ()
#8  0x080e2977 in PyEval_EvalCodeEx ()
#9  0x080e0fb3 in PyEval_EvalFrameEx ()
#10 0x080e2977 in PyEval_EvalCodeEx ()
#11 0x080e0fb3 in PyEval_EvalFrameEx ()
#12 0x080e2977 in PyEval_EvalCodeEx ()
#13 0x0816bcdc in ?? ()
#14 0x0806257a in PyObject_Call ()
#15 0x080df8d8 in PyEval_EvalFrameEx ()
#16 0x080e2977 in PyEval_EvalCodeEx ()
---Type <return> to continue, or q <return> to quit---
#17 0x0816bcdc in ?? ()
#18 0x0806257a in PyObject_Call ()
#19 0x0806a57c in ?? ()
#20 0x0806257a in PyObject_Call ()
#21 0x080db9f2 in PyEval_CallObjectWithKeywords ()
#22 0x00441cea in ?? () from /usr/lib/python2.6/lib-dynload/_tkinter.so
#23 0x006a6b66 in TclInvokeStringCommand () from /usr/lib/libtcl8.5.so.0
#24 0x006a8939 in ?? () from /usr/lib/libtcl8.5.so.0
#25 0x006f193e in ?? () from /usr/lib/libtcl8.5.so.0
#26 0x006effc1 in ?? () from /usr/lib/libtcl8.5.so.0
#27 0x006a9de1 in TclEvalObjEx () from /usr/lib/libtcl8.5.so.0
#28 0x0073ba76 in ?? () from /usr/lib/libtcl8.5.so.0
#29 0x006a8939 in ?? () from /usr/lib/libtcl8.5.so.0
#30 0x006f193e in ?? () from /usr/lib/libtcl8.5.so.0
#31 0x0073c2a9 in TclObjInterpProcCore () from /usr/lib/libtcl8.5.so.0
#32 0x0073c187 in TclObjInterpProc () from /usr/lib/libtcl8.5.so.0
#33 0x006a8939 in ?? () from /usr/lib/libtcl8.5.so.0
#34 0x006a91a6 in ?? () from /usr/lib/libtcl8.5.so.0
#35 0x006a8bfa in Tcl_EvalEx () from /usr/lib/libtcl8.5.so.0
#36 0x0058a329 in Tk_BindEvent () from /usr/lib/libtk8.5.so.0
#37 0x0059096c in TkBindEventProc () from /usr/lib/libtk8.5.so.0
#38 0x00599084 in Tk_HandleEvent () from /usr/lib/libtk8.5.so.0
#39 0x00599740 in ?? () from /usr/lib/libtk8.5.so.0
---Type <return> to continue, or q <return> to quit---
#40 0x0072b393 in Tcl_ServiceEvent () from /usr/lib/libtcl8.5.so.0
#41 0x0072b689 in Tcl_DoOneEvent () from /usr/lib/libtcl8.5.so.0
#42 0x0043faff in ?? () from /usr/lib/python2.6/lib-dynload/_tkinter.so
#43 0x080e114f in PyEval_EvalFrameEx ()
#44 0x080e2977 in PyEval_EvalCodeEx ()
#45 0x080e0fb3 in PyEval_EvalFrameEx ()
#46 0x080e2977 in PyEval_EvalCodeEx ()
#47 0x080e2a77 in PyEval_EvalCode ()
#48 0x0810071d in PyRun_FileExFlags ()
#49 0x08100982 in PyRun_SimpleFileExFlags ()
#50 0x0805df7c in Py_Main ()
#51 0x0805d13b in main ()