Thanks John. See also:
https://wiki.openjdk.java.net/display/OpenJFX/Using+an+IDE
There are several tricky issues around building, running and debugging
OpenJFX from within an IDE. The most important thing is to run the code
in the IDE rather than jfxrt.jar and the shared libraries that come
The easiest thing to do to debug JavaFX is to use a prebuilt JDK 8+ and attach
the sources from the JDK to your IDE.
Then you can set break-points in the JavaFX source and debug it (i.e. you don't
need to checkout and build openjfx at all).
This works fine if all you want to do is step through
