Seg fault occurs when dragging from a QTreeWidget that has a reimplemented mimeData func

Using Qt5.11.1, Python 3.6.5 , PySide2 on MacOS 10.13.5:

Dragging QTreeWidgetItems from a subclassed QTreeWidget that has a reimplemented mimeData function causes a segmentation fault on drag initiation. Using the same subclassed QTreeWidget without the reimplemented mimeData function results in normal behavior. Using PyQt5.11, no segmentation fault occurs.

A minimal example to recreate this behavior is attached. I apologize if this is a known issue and has been already reported.