Crash in "conhost.exe"

[Gisle Vanem]

Hello. My 1st post / issue on this project.

Running tiptip.exe on Win-10 causes (after approx. 1 sec), a crash in the underlaying conhost.exe process.
Here are some details:

• First the process-tree when WinDbg is blocking everything (since the 2nd instance of conhost.exe
  crashed and is Suspended):
  

• The call-stack of the offending thread:

ucrtbase!abort+0x4e
ucrtbase!terminate+0x1f
ucrtbase!__crt_state_management::wrapped_invoke<void +0x18
conhost!_scrt_unhandled_exception_filter+0x37
KERNELBASE!UnhandledExceptionFilter+0x1e7
ntdll!RtlUserThreadStart$filt$0+0xa2
ntdll!_C_specific_handler+0x96
ntdll!RtlpExecuteHandlerForException+0xf
ntdll!RtlDispatchException+0x244
ntdll!RtlRaiseException+0x1d7
KERNELBASE!RaiseException+0x69
ucrtbase!CxxThrowException+0xad
conhost!wil::details::ThrowResultExceptionInternal+0x4e
conhost!wil::details::ReportFailure+0x236aa
conhost!wil::details::ReportFailure_Hr+0x44
conhost!wil::details::in1diag3::Throw_Hr+0x26
conhost!Microsoft::Console::Render::Renderer::_PaintBufferOutput+0x1f9f1
conhost!Microsoft::Console::Render::Renderer::_PaintFrameForEngine+0x1a8
conhost!Microsoft::Console::Render::Renderer::PaintFrame+0x86
conhost!Microsoft::Console::Render::RenderThread::_ThreadProc+0x56
KERNEL32!BaseThreadInitThunk+0x14
ntdll!RtlUserThreadStart+0x21

• And in another conhost.exe thread:

ntdll!NtWaitForAlertByThreadId+0x14
ntdll!RtlpWaitOnAddressWithTimeout+0x81
ntdll!RtlpWaitOnAddress+0xae
ntdll!RtlpWaitOnCriticalSection+0xfd
ntdll!RtlpEnterCriticalSectionContended+0x1c4
ntdll!RtlEnterCriticalSection+0x42
conhost!Microsoft::Console::Interactivity::Win32::Window::ConsoleWindowProc+0x68
conhost!Microsoft::Console::Interactivity::Win32::Window::s_ConsoleWindowProc+0x53
user32!UserCallWinProcCheckWow+0x515
user32!DispatchMessageWorker+0x49d
conhost!ConsoleInputThreadProcWin32+0xa6
KERNEL32!BaseThreadInitThunk+0x14
ntdll!RtlUserThreadStart+0x21

• Yet another conhost.exe thread:

ntdll!NtWaitForAlertByThreadId+0x14
ntdll!RtlpWaitOnAddressWithTimeout+0x81
ntdll!RtlpWaitOnAddress+0xae
ntdll!RtlpWaitOnCriticalSection+0xfd
ntdll!RtlpEnterCriticalSectionContended+0x1c4
ntdll!RtlEnterCriticalSection+0x42
conhost!ApiRoutines::GetConsoleScreenBufferInfoExImpl+0x20
conhost!ApiDispatchers::ServerGetConsoleScreenBufferInfo+0x95
conhost!ApiSorter::ConsoleDispatchRequest+0x19c
conhost!ConsoleIoThread+0x116
KERNEL32!BaseThreadInitThunk+0x14
ntdll!RtlUserThreadStart+0x21

I'm off-cource not using the Windows Legacy Console with Rich and TipTop (would that work?)
But I'm not sure if my TCC shell is causing this. And launching tiptop.exe from a cmd.exe window does not work at all!
A tiptop.exe --log tiptop.log gives no clue.

And BTW, I also note (from Process Explorer) that the number of threads in the above python.exe instance quickly grows to 40!
Not sure if it's related to the crash in conhost.exe or what. But exiting from WinDbg, crashes python.exe too. No surprise I guess.