Using Tcl/Tk 8.5.13 I get a bus error (tested with OSX 10.6.2 and 10.8.3) if I type the following test lines:
package require Tk
font configure TkDefaultFont -size 10
ttk::label .status -relief sunken
menu .mbar
menu .mbar.apple
.mbar add cascade -menu .mbar.apple
.mbar.apple add command -label hello
. configure -menu .mbar
font configure TkDefaultFont -size 12
The console log shows amongst others:
Thread 0 Crashed: Dispatch queue: com.apple.main-thread
0 com.tcltk.tklibrary 0x000d333b TkpConfigureMenuEntry + 2251
1 com.tcltk.tklibrary 0x00049948 MenuWorldChanged + 69
2 com.tcltk.tklibrary 0x0001f05d RecomputeWidgets + 42
3 com.tcltk.tklibrary 0x0001f069 RecomputeWidgets + 54
4 com.tcltk.tcllibrary 0x001f5605 TclServiceIdle + 61
5 com.tcltk.tcllibrary 0x001d79a3 Tcl_DoOneEvent + 342
6 com.tcltk.tklibrary 0x0001d4c0 Tk_MainLoop + 37
7 com.tcltk.tklibrary 0x0002b612 Tk_MainEx + 2041
8 wish 0x00004590 main + 41
9 wish 0x000044b9 start + 53
The complete log file is attached. Tcl/Tk 8.5.9 worked fine.