Why is Glance Launch Mode always disabled in the simulator?

I'm trying to make a "widget" with a glance.

(:glance)
class MyWidgetApp extends Application.AppBase {

    function initialize() {
        AppBase.initialize();
    }

    function getGlancelView() as [ GlanceView ] or [ GlanceView, GlanceViewDelegate ] or Null {
        return [ new MyGlanceView() ];
    }

    function getGlanceTheme() as AppBase.GlanceTheme {
        return AppBase.GLANCE_THEME_DEFAULT;
    }

    // Return the initial view of your application here
    function getInitialView() as [Views] or [Views, InputDelegates] {
        return [ new MyWidgetView() ];
    }

}

(:glance)
class MyGlanceView extends WatchUi.GlanceView {
    function initialize() {
        GlanceView.initialize();
        System.println("MyGlanceView");
    }
    function onUpdate(dc as Dc) as Void {
        dc.setColor(Graphics.COLOR_WHITE, Graphics.COLOR_BLACK);
        dc.clear();
        dc.drawText(dc.getWidth() / 2, dc.getHeight() / 2, Graphics.FONT_SMALL, "glance test", Graphics.TEXT_JUSTIFY_CENTER | Graphics.TEXT_JUSTIFY_VCENTER);
    }
}


(:glance)
class MyWidgetView extends WatchUi.View {
    function initialize() {
        View.initialize();
        System.println("MyWidgetView");
    }
    function onUpdate(dc as Dc) as Void {
        dc.setColor(Graphics.COLOR_WHITE, Graphics.COLOR_BLACK);
        dc.clear();
        dc.drawText(dc.getWidth() / 2, dc.getHeight() / 2, Graphics.FONT_SMALL, "widget test", Graphics.TEXT_JUSTIFY_CENTER | Graphics.TEXT_JUSTIFY_VCENTER);
    }
}

In the manifest I tried it both as Widget and as WatchApp, minApiLevel: 3.2.0.

I tried it in SDK 8.3.0 and 8.4.0 on fr955.

No matter what I do the Settings > Glance Launch Mode is grayed out and of course getGlanceView is never called.

What should I do to be able to debug my glance view in the simulator?