Segfault on PyQt6 6.9.1

[Phil Thompson]

On 10/06/2025 13:37, Jonathan Coates wrote:
> Hi all,
> 
> I recently updated to the PyQt6 6.9.1, and started experiencing
> SIGSEGVs when closing an application. I've narrowed it down to the
> attached example, and also attached the stacktrace from where the
> segfault occurs. This is specific to 6.9.1, and does not occur with
> 6.9.0.
> 
> The crash occurs when the QtWidgets.QMainWindow is disposed — either
> with a `del main_window` or (in the attached example) the stack frame
> itself is disposed of. I'm happy to debug this further — currently
> trying to get a debug build of PyQt 6 working, but wanted to check if
> a) this was a known issue and b) if there were any tips for debugging
> the generated SIP code?
> 
> Many thanks,
> 
> Jonathan

I get a segfault with PyQt v6.9.1 and Qt v6.9.1 but not with Qt v6.9.0. 
PyQt v6.9.1 is built against Qt v6.9.0 - that shouldn't make a 
difference. See also...

https://www.riverbankcomputing.com/static/Docs/PyQt6/gotchas.html#crashes-on-exit

Phil