Just upgraded to Sonoma and Xcode 15. When I try debugging my SwiftUI app, an assertion fires in AppKit (see below) on app start. I cleaned and tried debugging again and still get the same assertion. I also tried commenting out the app's toolbar but still got the same assertion. The same code worked before upgrading. Ideas?
*** Assertion failure in -[NSWindowSectionController registerSeparator:], NSWindowSectionController.m:529
An uncaught exception was raised
Cannot register more than one NSTrackingSeparatorToolbarItem that tracks the same divider
(
0 CoreFoundation 0x0000000185f3c8c0 __exceptionPreprocess + 176
1 libobjc.A.dylib 0x0000000185a35eb4 objc_exception_throw + 60
2 Foundation 0x000000018708318c -[NSCalendarDate initWithCoder:] + 0
3 AppKit 0x000000018a219cb8 -[NSWindowSectionController registerSeparator:] + 304
4 AppKit 0x000000018975952c -[NSToolbar _newItemFromItemIdentifier:propertyListRepresentation:requireImmediateLoad:willBeInsertedIntoToolbar:] + 384
5 AppKit 0x000000018975b2f4 -[NSToolbar _loadAllPlaceholderItems] + 292
6 AppKit 0x000000018976995c -[NSToolbar items] + 36
7 AppKit 0x0000000189769484 -[NSToolbarView _syncItemSet] + 84
8 AppKit 0x000000018a0efea8 -[NSToolbarView _syncItemSetAndUpdateItemViewersWithSEL:setNeedsModeConfiguration:setNeedsDisplay:updateKeyLoop:] + 48
9 AppKit 0x000000018975ace8 -[NSToolbarView setToolbar:] + 280
10 AppKit 0x000000018a0ee330 +[NSToolbarView newViewForToolbar:inWindow:] + 88
11 AppKit 0x000000018975a090 -[NSToolbar _loadViewIfNecessary] + 108
12 AppKit 0x0000000189759fc0 -[NSToolbar _windowWillShowToolbar] + 68
13 AppKit 0x0000000189759f08 -[NSWindow _showToolbar:animate:] + 128
14 AppKit 0x0000000189759e18 -[NSToolbar _show:animate:] + 92
15 AppKit 0x0000000189759d84 -[NSToolbar _toggleShown:animate:] + 88
16 AppKit 0x0000000189756f2c -[NSWindow setToolbar:] + 396
17 SwiftUI 0x00000001b14a73c4 OUTLINED_FUNCTION_0 + 78340
18 SwiftUI 0x00000001b14a65c8 OUTLINED_FUNCTION_0 + 74760
19 SwiftUI 0x00000001b14a6360 OUTLINED_FUNCTION_0 + 74144
20 SwiftUI 0x00000001b14a5a6c OUTLINED_FUNCTION_0 + 71852
21 SwiftUI 0x00000001b139f294 OUTLINED_FUNCTION_16 + 66792
22 SwiftUI 0x00000001b139f480 OUTLINED_FUNCTION_16 + 67284
23 AppKit 0x00000001896b4ae0 -[NSView _setWindow:] + 1788
24 AppKit 0x00000001896bc1cc -[NSView addSubview:] + 212
25 AppKit 0x00000001896c1ca0 -[NSFrameView addSubview:] + 52
26 AppKit 0x00000001896c1c54 -[NSThemeFrame addSubview:] + 452
27 AppKit 0x00000001896c1678 -[NSView addSubview:positioned:relativeTo:] + 372
28 AppKit 0x00000001896c1480 -[NSThemeFrame addSubview:positioned:relativeTo:] + 52
29 AppKit 0x00000001896c1434 -[NSThemeFrame _addKnownSubview:positioned:relativeTo:] + 44
30 AppKit 0x00000001896dbcf0 -[NSWindow setContentView:] + 292
31 AppKit 0x00000001898719c4 -[NSWindow _contentViewControllerChanged] + 364
32 AppKit 0x00000001896e2dc4 NSPerformVisuallyAtomicChange + 108
33 AppKit 0x00000001898717e4 -[NSWindow setContentViewController:] + 132
34 SwiftUI 0x00000001b14a2628 OUTLINED_FUNCTION_0 + 58472
35 SwiftUI 0x00000001b0d80cc0 OUTLINED_FUNCTION_29 + 9656
36 SwiftUI 0x00000001b0d81580 OUTLINED_FUNCTION_29 + 11896
37 SwiftUI 0x00000001b10b7f58 OUTLINED_FUNCTION_15 + 1044
38 SwiftUI 0x00000001b149d434 OUTLINED_FUNCTION_0 + 37492
39 SwiftUI 0x00000001b1499638 OUTLINED_FUNCTION_0 + 21624
40 SwiftUI 0x00000001b14983e4 OUTLINED_FUNCTION_0 + 16932
41 SwiftUI 0x00000001b1bc4624 OUTLINED_FUNCTION_93 + 3084
42 SwiftUI 0x00000001b1bc4960 OUTLINED_FUNCTION_93 + 3912
43 CoreFoundation 0x0000000185ebc780 __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148
44 CoreFoundation 0x0000000185f509a8 ___CFXRegistrationPost_block_invoke + 88
45 CoreFoundation 0x0000000185f508f0 _CFXRegistrationPost + 440
46 CoreFoundation 0x0000000185e8b434 _CFXNotificationPost + 764
47 Foundation 0x0000000186f7cc74 -[NSNotificationCenter postNotificationName:object:userInfo:] + 88
48 AppKit 0x00000001896a8960 -[NSApplication _postDidFinishNotification] + 284
49 AppKit 0x00000001896a8710 -[NSApplication _sendFinishLaunchingNotification] + 172
50 AppKit 0x00000001896a6c58 -[NSApplication(NSAppleEventHandling) _handleAEOpenEvent:] + 504
51 AppKit 0x00000001896a6854 -[NSApplication(NSAppleEventHandling) _handleCoreEvent:withReplyEvent:] + 492
52 Foundation 0x0000000186fa5194 -[NSAppleEventManager dispatchRawAppleEvent:withRawReply:handlerRefCon:] + 316
53 Foundation 0x0000000186fa4f88 _NSAppleEventManagerGenericHandler + 80
54 AE 0x000000018cdeed8c _AppleEventsCheckInAppWithBlock + 13808
55 AE 0x000000018cdee6b4 _AppleEventsCheckInAppWithBlock + 12056
...
)