2020.1.0a11 - Layout update is struggling to process current layout ...

I'm using custom layouts in all the versions of Unity I'm working with. Up to now, I didn't have issues using them in alpha versions.

I'm now getting the following message on a regular basis; I have no idea how to reproduce the problem.

Spoiler: message

Code (CSharp):

1. Layout update is struggling to process current layout (consider simplifying to avoid recursive layout): VisualElement unity-panel-container13 (x:0.00, y:0.00, width:351.00, height:773.00) world rect: (x:0.00, y:0.00, width:351.00, height:773.00)
2. 0x00000001428E848C (Unity) StackWalker::GetCurrentCallstack
3. 0x00000001428EB991 (Unity) StackWalker::ShowCallstack
4. 0x0000000141000FC5 (Unity) GetStacktrace
5. 0x00000001435DC1BE (Unity) DebugStringToFile
6. 0x0000000142960165 (Unity) DebugLogHandler_CUSTOM_Internal_Log
7. 0x0000000066F6695B (Mono JIT Code) (wrapper managed-to-native) UnityEngine.DebugLogHandler:Internal_Log (UnityEngine.LogType,UnityEngine.LogOption,string,UnityEngine.Object)
8. 0x0000000066F668AB (Mono JIT Code) UnityEngine.DebugLogHandler:LogFormat (UnityEngine.LogType,UnityEngine.Object,string,object[])
9. 0x0000000066F66640 (Mono JIT Code) UnityEngine.Logger:Log (UnityEngine.LogType,object)
10. 0x0000000066F66505 (Mono JIT Code) UnityEngine.Debug:LogError (object)
11. 0x000000006556DA7B (Mono JIT Code) UnityEngine.UIElements.UIRLayoutUpdater:Update ()
12. 0x000000006555D0FE (Mono JIT Code) UnityEngine.UIElements.VisualTreeUpdater:UpdateVisualTreePhase (UnityEngine.UIElements.VisualTreeUpdatePhase)
13. 0x000000006555CFD3 (Mono JIT Code) UnityEngine.UIElements.Panel:ValidateLayout ()
14. 0x000000006555CADD (Mono JIT Code) UnityEngine.UIElements.UIElementsUtility:DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel)
15. 0x000000006555C70B (Mono JIT Code) UnityEngine.UIElements.UIElementsUtility:ProcessEvent (int,intptr)
16. 0x000000006555C46D (Mono JIT Code) UnityEngine.GUIUtility:ProcessEvent (int,intptr)
17. 0x000000006555C52A (Mono JIT Code) (wrapper runtime-invoke) <Module>:runtime_invoke_bool_int_intptr (object,intptr,intptr,intptr)
18. 0x000007FEBDD3CE80 (mono-2.0-bdwgc) [mini-runtime.c:2809] mono_jit_runtime_invoke
19. 0x000007FEBDCC2142 (mono-2.0-bdwgc) [object.c:2921] do_runtime_invoke
20. 0x000007FEBDCCB13F (mono-2.0-bdwgc) [object.c:2968] mono_runtime_invoke
21. 0x0000000142868D6E (Unity) scripting_method_invoke
22. 0x00000001428628DD (Unity) ScriptingInvocation::Invoke
23. 0x000000014285CACA (Unity) ScriptingInvocation::Invoke<bool>
24. 0x000000013FC95315 (Unity) Scripting::UnityEngine::GUIUtilityProxy::ProcessEvent
25. 0x00000001406018FC (Unity) GUIView::ProcessRetainedMode
26. 0x000000014102680D (Unity) GUIView::OnInputEvent
27. 0x000000014060180C (Unity) GUIView::ProcessInputEvent
28. 0x00000001410282E5 (Unity) GUIView::ProcessEventMessages
29. 0x0000000141021049 (Unity) GUIView::GUIViewWndProc
30. 0x00000000779D9A8D (USER32) TranslateMessageEx
31. 0x00000000779D9786 (USER32) TranslateMessage
32. 0x000000014102565E (Unity) MainMessageLoop
33. 0x000000014102F419 (Unity) WinMain
34. 0x000000014407AD92 (Unity) __scrt_common_main_seh
35. 0x00000000778B556D (kernel32) BaseThreadInitThunk
36. 0x0000000077B1385D (ntdll) RtlUserThreadStart

I join the LastLayout.dwlt below if people what to take a look at it.

 

Thank you!

 

This has come back from the dead in Unity 2022.3.*.

I see people have logged bugs on it, and had them closed as "WONTFIX" because the Unity team can't reproduce them.

Before I waste time creating a bug that gets immediately closed because it's got too little info for Unity QA ... what debugging can I do locally to help diagnose/trace/narrow this down?

I'm seeing it:

1. 100% of the time in a specific Inspector in a specific Scene
2. 0% of the time in that same Inspector in hundreds of other scenes - many of them VASTLY more complex than this scene
3. I changed nothing in the Inspector; the error just materialized in-Editor today after recompiling an unrelated piece of code (!) that exists in an entirely separate Unity Package / asmdef

... and I suspect it's going to vanish randomly when I recompile (?)