Library source handling does not handle module-info

After creating a library from javafx-sdk-13.0.2, including source (had to unzip source and add each of the 7 top level zip directories as a folder), almost all import statements are red underlined with an error. From within a javafx source file, "Go To Source", "Go To Declaration" do not work. For example for Label.java there is

import javafx.beans.property.ObjectProperty;

in the editor we get the popup error

package javafx.beans.property is not visible
(package javafx.beans.property is declared in the unnamed module, but module javafx.beans.property does not read it)