QGIS 3 crashes when QgsExtentGroupBox.setOriginalExtent() is called

Question

Below is the relevant code. I am using QgsProjectionSelectionWidget to get the CRS.

    canvas_extent = self.canvas.extent()

    transformer = QgsCoordinateTransform(
        self.canvas.mapSettings().destinationCrs(),
        self.input_projection_cbo.crs(),
        QgsProject.instance()
    )

    transformer.setDestinationCrs(
        self.input_projection_cbo.crs()
    )
    transformed_extent = transformer.transform(canvas_extent)

    self.extent_box.setOriginalExtent(
        transformed_extent,
        QgsCoordinateReferenceSystem(
            self.input_projection_cbo.crs().authid()
        )
    )

    self.extent_box.setOutputCrs(
        QgsCoordinateReferenceSystem(
            self.input_projection_cbo.crs().authid()
        )
    )
    self.extent_box.setOutputExtentFromOriginal()
    self.extent_box.setCurrentExtent(
        transformed_extent,
        QgsCoordinateReferenceSystem(
            self.input_projection_cbo.crs().authid()
        )

    )

Below is the entire report.

h2. User Feedback
h2. Report Details
*Crash ID*: 8e827b9e58264385e7a945fbe0ac6df5b4daf9a5
*Stack Trace*

 QgsExtentGroupBox::setOriginalExtent :
PyInit__gui :
PyCFunction_FastCallDict :
PyObject_GenericGetAttr :
PyEval_EvalFrameDefault :
PyFunction_FastCallDict :
PyObject_CallFunctionObjArgs :
PyObject_Call :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
QMetaObject::activate :
QGroupBox::childEvent :
QGroupBox::mouseReleaseEvent :
QgsPresetSchemeColorRamp::clone :
QWidget::event :
QGroupBox::event :
QgsPresetSchemeColorRamp::clone :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QApplicationPrivate::sendMouseEvent :
QSizePolicy::QSizePolicy :
QSizePolicy::QSizePolicy :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QGuiApplicationPrivate::processMouseEvent :
QWindowSystemInterface::sendWindowSystemEvents :
QEventDispatcherWin32::processEvents :
CallWindowProcW :
DispatchMessageW :
QEventDispatcherWin32::processEvents :
qt_plugin_query_metadata :
QEventLoop::exec :
QCoreApplication::exec :
main :
BaseThreadInitThunk :
RtlUserThreadStart :

*QGIS Info*
QGIS Version: 3.2.1-Bonn
QGIS code revision: commit:1edf372fb8
Compiled against Qt: 5.9.2
Running against Qt: 5.9.2
Compiled against GDAL: 2.2.4
Running against GDAL: 2.2.4

*System Info*
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 10.0.17134

Answer 1

I found out that the problem is not on the above code. The crash is most likely related to me hiding the extent groupbox buttons using Qt methods. I had to delete them because hiding did not work as they still reappeared. The code below used to work on QGIS 2.18 but was not working on QGIS 3.2 and later. Anyways I decided not to hide it due to the crash. Thus, I commented out the code below.

    for button in self.extent_box.findChildren(QPushButton):
        button.setHidden(True)
        button.parent().setHidden(True)
        button.deleteLater()
        button.parent().deleteLater()