gwt - GWT Super Dev Mode variable referenceError: variable is not defined

Question

I'm using GWT Super Dev Mode and the Chrome debugger. Some (not all) variables won't let me examine their values, either by hovering or by right-click -> Evaluate in Console. The latter gives "ReferenceError: is not defined. It reminds me of an earlier environment where the compiler optimizer simply removed variables of short duration. Does anyone know why this happens or how to stop it? Here is a code example:

    public AbstractModal( final String title, final String width )
{
    this( title, width, ( int )( Window.getClientHeight( ) * AbstractModal.MaxHeightPercentage ) + "px" );
}