Qt has caught an exception thrown from an event handler

[trayres]

Qt has caught an exception thrown from an event handler. Throwing
exceptions from an event handler is not supported in Qt.
You must not let any exception whatsoever propagate through Qt code.
If that is not possible, in Qt 5 you must at least reimplement
QCoreApplication::notify() and catch all exceptions there.

QBackingStore::endPaint() called with active painter; did you forget to destroy it or call QPainter::end() on it?

I can trigger this repeatably.

"nextpnr-ecp5" -- Next Generation Place and Route (Version nextpnr-0.5-98-gb36e8a30)