SOFT-ASSERTs when clicking on the alias icon

Whenever I click on the icon next to the id field of my top-level Window I get these SOFT ASSERTs:

SOFT ASSERT: "offset > 0" in file /home/qt/work/build/qt-creator/src/plugins/qmldesigner/designercore/model/rewriterview.cpp, line 744
void QmlDesigner::RewriterView::setupCanonicalHashes() const no offset ModelNode(0, "QtQuick.Rectangle", "")
SOFT ASSERT: "!m_canonicalIntModelNode.isEmpty()" in file /home/qt/work/build/qt-creator/src/plugins/qmldesigner/designercore/model/rewriterview.cpp, line 1085