Hello, I encountered this bug in PySide6, but I had some wonderful help from someone on that side of the tracker to determine this is a bug in the Qt library.

 ASSERT: "visual != -1" in file qtbase/src/widgets/itemviews/qheaderview.cpp, line 1239

This is what they found to be the issue. The method is protected by an assertion, but that may not be sufficient.

As the summary suggests, when a logicalIndex is given, and there is no model set, or there is but it has no columnCount set, the method crashes.

If the columnCount is set, the value can even be outside the range [0, columnCount), and it won't crash.

Let me know if you need more information that I am able to provide.

The (out of scope) PySide bug report I made is here, in case you would like the minimal example I made in python 3.10.5: https://bugreports.qt.io/browse/PYSIDE-2054