Version 5.12.3 introduced a regression, problem also occurs on 5.13.0-beta3. Version 5.12.2 and earlier work correctly.

Application crashes with Segmentation fault. It happens always when string (url to QML file) is passed to StackView and few other conditions are met.

var url = Qt.resolvedUrl("MainPage.qml")
pageStack.push(url)

I works correctly when an Object is passed:

var url = Qt.resolvedUrl("MainPage.qml")
pageStack.push(Qt.createComponent(url))

I attached sample applications (with C++ and pure QML). I simplified example as much as I could but quicte strange combination of binding is needed to reproduce this issue.

I also attached stack-trace.