10.8, 10.9, NSDocument, TypeError, "cannot change a method"

Erik van Blokland <[email protected]> Wed, 28 Aug 2013 15:25:57 +0200
Newsgroups gmane.comp.python.pyobjc.devel
Message-ID <[email protected]>
Hi

I'm aware this is a bit of a long shot, but maybe someone recognises this issue. 

I have a python application generated with pyobjc on OSX 10.8.
	- Stock python Python 2.7.2 (default, Oct 11 2012, 20:14:37)
	- presumably also a stock objc 2.3.2a0, (at /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC/objc/__init__.py)

On 10.7 and 10.8 I can get a new window when I select New from the menu. 
On 10.9 (the current developer release) I get an exception, "cannot change a method" - see below. The app continues to run, but there isn't much of a traceback. 

Looking at the dump, I get the impression something goes wrong when NSDocumentController calls newDocument: My NSDocument subclass doesn't contain anything suspicious. I think I'm using up to date calls for reading and writing. Methods in my NSDocument subclass:  
	init
	readFromURL_ofType_error_
	writeSafelyToURL_ofType_forSaveOperation_error_
	makeWindowControllers
	+ a couple of callbacks for menus. 

I've tested this with two independent projects, both get the same exception. 
Any guesses would be welcome, thanks.
Erik

Exception Name: OC_PythonException
Description: <type 'exceptions.TypeError'>: cannot change a method
User Info: {
   "__pyobjc_exc_traceback__" = "<traceback object at 0x112ea8680>";
   "__pyobjc_exc_type__" = "<type 'exceptions.TypeError'>";
   "__pyobjc_exc_value__" = "TypeError('cannot change a method',)";
}

0   CoreFoundation                      0x00007fff886878ce __exceptionPreprocess + 174
1   libobjc.A.dylib                     0x00007fff8f656f51 objc_exception_throw + 43
2   CoreFoundation                      0x00007fff8872d619 -[NSException raise] + 9
3   _objc.so                            0x000000010acb1366 PyObjCFFI_MakeClosure + 4418
4   libffi.dylib                        0x00007fff91c02a1f ffi_closure_unix64_inner + 509
5   libffi.dylib                        0x00007fff91c0211e ffi_closure_unix64 + 70
6   AppKit                              0x00007fff888e0b0f -[NSDocumentController newDocument:] + 36
7   AppKit                              0x00007fff88af90da -[NSApplication sendAction:to:from:] + 327
8   AppKit                              0x00007fff88c1d548 -[NSMenuItem _corePerformAction] + 394
9   AppKit                              0x00007fff88c1d234 -[NSCarbonMenuImpl performActionWithHighlightingForItemAtIndex:] + 117
10  AppKit                              0x00007fff8893e72d -[NSMenu _internalPerformActionForItemAtIndex:] + 35
11  AppKit                              0x00007fff8893e5a5 -[NSCarbonMenuImpl _carbonCommandProcessEvent:handlerCallRef:] + 104
12  AppKit                              0x00007fff88c16442 NSSLMMenuEventHandler + 716
13  HIToolbox                           0x00007fff8ad8a9a4 _ZL23DispatchEventToHandlersP14EventTargetRecP14OpaqueEventRefP14HandlerCallRec + 892
14  HIToolbox                           0x00007fff8ad89f67 _ZL30SendEventToEventTargetInternalP14OpaqueEventRefP20OpaqueEventTargetRefP14HandlerCallRec + 385
15  HIToolbox                           0x00007fff8ad9f4f0 SendEventToEventTarget + 40
16  HIToolbox                           0x00007fff8add4380 _ZL18SendHICommandEventjPK9HICommandjjhPKvP20OpaqueEventTargetRefS5_PP14OpaqueEventRef + 420
17  HIToolbox                           0x00007fff8ad7b818 SendMenuCommandWithContextAndModifiers + 59
18  HIToolbox                           0x00007fff8ad7b7ba SendMenuItemSelectedEvent + 178
19  HIToolbox                           0x00007fff8ad7b697 _ZL19FinishMenuSelectionP13SelectionDataP10MenuResultS2_ + 94
20  HIToolbox                           0x00007fff8ad58d95 _ZL14MenuSelectCoreP8MenuData5PointdjPP13OpaqueMenuRefPt + 718
21  HIToolbox                           0x00007fff8ad58261 _HandleMenuSelection2 + 446
22  AppKit                              0x00007fff88ae8109 _NSHandleCarbonMenuEvent + 284
23  AppKit                              0x00007fff88a13f1e _DPSNextEvent + 2170
24  AppKit                              0x00007fff88a1328b -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 122
25  AppKit                              0x00007fff88a0b53c -[NSApplication run] + 553
26  AppKit                              0x00007fff889b5563 NSApplicationMain + 940
27  _AppKit.so                          0x000000010cbfcbbe init_AppKit + 8609
28  Python                              0x000000010ab025a9 PyEval_EvalFrameEx + 9244
29  Python                              0x000000010ab00147 PyEval_EvalCodeEx + 1934
30  Python                              0x000000010ab068df _PyEval_SliceIndex + 989
31  Python                              0x000000010ab0263a PyEval_EvalFrameEx + 9389
32  Python                              0x000000010ab00147 PyEval_EvalCodeEx + 1934
33  Python                              0x000000010aaff9b3 PyEval_EvalCode + 54
34  Python                              0x000000010ab3bc70 PyParser_ASTFromFile + 299
35  Python                              0x000000010ab3bd3c PyRun_FileExFlags + 165
36  Python                              0x000000010aafa830 _PyBuiltin_Init + 4737
37  Python                              0x000000010ab025a9 PyEval_EvalFrameEx + 9244
38  Python                              0x000000010ab00147 PyEval_EvalCodeEx + 1934
39  Python                              0x000000010ab068df _PyEval_SliceIndex + 989
40  Python                              0x000000010ab0263a PyEval_EvalFrameEx + 9389
41  Python                              0x000000010ab00147 PyEval_EvalCodeEx + 1934
42  Python                              0x000000010aaff9b3 PyEval_EvalCode + 54
43  Python                              0x000000010ab3bc70 PyParser_ASTFromFile + 299
44  Python                              0x000000010ab3bd3c PyRun_FileExFlags + 165
45  Python                              0x000000010ab3b726 PyRun_SimpleFileExFlags + 410
46  Superpolator                        0x000000010a988e79 main + 5965
47  Superpolator                        0x000000010a987cad main + 1409
48  libdyld.dylib                       0x00007fff8d81160d start + 1
49  ???                                 0x0000000000000001 0x0 + 1
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