Have the following QML files:

Blah.qml:

Text {
    id: txt
    property alias font: txt.font
    width: 640
    height: 480
}

Main.qml:

Rectangle {
    width: 200
    height: 323
    Blah {
        font.pixelSize: 24
        text: "boo hoo"
    }
}

In the snippet below, font will have red underline below it with the message "font does not have members". However, the code compiles and works correctly.