[qmltc] Customizing Overlay.modal attached property causes compilation errors

import QtQuick
import QtQuick.Templates

Popup {
    Overlay.modal: Rectangle {
        color: 'grey'
    }
}

...
    auto o = new MyPopup_Rectangle(creator, engine, this);
...

.qmltc\test\mypopup.cpp(375): error C2061: syntax error: identifier 'MyPopup_Rectangle'
.qmltc\test\mypopup.cpp(376): error C3536: 'o': cannot be used before it is initialized
...