QtGraphicalEffects print out "binding loop" warnings

When using the Qt Graphical Effet Module, I get a lot of warnings:
file:///Users/gunnar/dev/qt5/qtbase/qml/QtGraphicalEffects/private/GaussianDirectionalBlur.qml:66:5: QML SourceProxy: Binding loop detected for property "output"

This is reproducable by running qtgraphicaleffect/tests/manual/testbed/testBed.qml

This does not seem to affect the visual result as effects apply as expected.