qmlscene -style material file.qml says "QApplication: invalid style override passed"

[jimav]

qmlscene -qt=5 -style material file.qml
prints
  QApplication: invalid style override passed, ignoring it.
on the terminal.

This does not happen when using the environment variable method, e.g.
  QT_QUICK_CONTROLS_STYLE=material qmlscene -qt=5 file.qml

The documentation for how this is supposed to work is at
  https://doc.qt.io/qt-5/qtquickcontrols2-styles.html#using-styles-in-qt-quick-controls-2

I'm reporting this to ubuntu because it might be due to packaging or patching done for Ubuntu. I can not conveniently try a pristine upstream version of Qt, so hoping the Qt Ubuntu maintainer can quickly determine if this is an upstream bug or not.

I'll attach a trivial test file which demonstrates the problem

STEPS TO REPRODUCE:
  qmlscene -style material test.qml # test.qml attached

ACTUAL RESULTS:
  Prints warning about invalid style on the terminal

EXPECTED RESULTS:
  Silent obedience

[Juhani Numminen (jsonic)]

Reassigned to qtdeclarative-opensource-src which is responsible for the qmlscene binary. qtchooser is just a "wrapper to select between Qt development binary versions."

[jimav (james-avera)]

Ok, thanks. FYI the underlying qmlscene executable (/usr/lib/qt5/bin/qmlscene)
is provided by the "qmlscene" package in Ubuntu 18.04.

[jimav (james-avera)]

Upstream bug: https://bugreports.qt.io/browse/QTBUG-73818