Part of custom control rendered twice on 2nd run

[pilhuhn]

I have a custom control for charts in https://github.com/pilhuhn/hawkfx which displays and works nicely on the first invocation.
When I stop and restart the program, a part of the custom control is rendered twice.
If I clear assets/.jrubyfx_cache/ the rendering is again correct. See below for screenshots

I have created a smaller sample app

fx-bug.zip

and the output of two runs of the sample app on the command line looks like:

snert:fx-bug hrupp$ jruby simple_test.rb
/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-fxmlloader-0.4.1-java/lib/fxmlloader/elts.rb:158: warning: `<<' after local variable or literal is interpreted as binary operator
/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-fxmlloader-0.4.1-java/lib/fxmlloader/elts.rb:158: warning: even though it seems like here document
saved /Users/hrupp/src/fx-bug/assets/.jrubyfx_cache/8a27485946241550e0f6e0750e4975ba4f113a65.rb to cache
saved /Users/hrupp/src/fx-bug/assets/.jrubyfx_cache/5b514f096053457c3854b2af3a1b05170f4e3533.rb to cache
snert:fx-bug hrupp$ jruby simple_test.rb
/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-fxmlloader-0.4.1-java/lib/fxmlloader/elts.rb:158: warning: `<<' after local variable or literal is interpreted as binary operator
/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-fxmlloader-0.4.1-java/lib/fxmlloader/elts.rb:158: warning: even though it seems like here document
JIT compiled method for file:/Users/hrupp/src/fx-bug/assets/ChartView.fxml FAILED with error:
Cannot create instance of javafx.scene.chart.LineChart with given set of properties: [prefHeight, visible]
com.sun.javafx.fxml.builder.ProxyBuilder.build(com/sun/javafx/fxml/builder/ProxyBuilder.java:247)
java.lang.reflect.Method.invoke(java/lang/reflect/Method.java:498)
org.jruby.javasupport.JavaMethod.invokeDirectWithExceptionHandling(org/jruby/javasupport/JavaMethod.java:438)
org.jruby.javasupport.JavaMethod.invokeDirect(org/jruby/javasupport/JavaMethod.java:302)
RUBY.new(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-fxmlloader-0.4.1-java/lib/jrubyfx-fxmlloader.rb:228)
RUBY.build(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/module.rb:92)
RUBY.block in __build_via_jit(/Users/hrupp/src/fx-bug/assets/.jrubyfx_cache/5b514f096053457c3854b2af3a1b05170f4e3533.rb:44)
org.jruby.RubyBasicObject.yieldUnder(org/jruby/RubyBasicObject.java:1744)
org.jruby.RubyBasicObject.specificEval(org/jruby/RubyBasicObject.java:1767)
org.jruby.RubyBasicObject.instance_eval(org/jruby/RubyBasicObject.java:1647)
RUBY.with(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/module.rb:49)
RUBY.__build_via_jit(/Users/hrupp/src/fx-bug/assets/.jrubyfx_cache/5b514f096053457c3854b2af3a1b05170f4e3533.rb:19)
RUBY.__build_via_jit(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-fxmlloader-0.4.1-java/lib/fxmlloader/fxml_jit_info.rb:89)
RUBY.load(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-fxmlloader-0.4.1-java/lib/jrubyfx-fxmlloader.rb:314)
RUBY.load_fxml(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/controller.rb:260)
RUBY.initialize_controller(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/controller.rb:242)
RUBY.new(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/controller.rb:154)
RUBY.build(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/module.rb:92)
RUBY.method_missing(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/dsl.rb:108)
RUBY.initialize(/Users/hrupp/src/fx-bug/lib/simple_controller.rb:13)
org.jruby.RubyClass.finvoke(org/jruby/RubyClass.java:543)
org.jruby.RubyBasicObject.send19(org/jruby/RubyBasicObject.java:1640)
org.jruby.RubyKernel.send19(org/jruby/RubyKernel.java:1998)
RUBY.finish_initialization(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/controller.rb:271)
RUBY.load_into(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/controller.rb:136)
RUBY.fxml(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/core_ext/stage.rb:82)
simple_test.block in start(simple_test.rb:11)
org.jruby.RubyBasicObject.yieldUnder(org/jruby/RubyBasicObject.java:1744)
org.jruby.RubyBasicObject.specificEval(org/jruby/RubyBasicObject.java:1767)
org.jruby.RubyBasicObject.instance_eval(org/jruby/RubyBasicObject.java:1647)
RUBY.with(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/module.rb:49)
simple_test.start(simple_test.rb:10)
RUBY.block in launch_app_after_platform(/Users/hrupp/.rvm/gems/jruby-9.1.0.0/gems/jrubyfx-1.1.1-java/lib/jrubyfx/java_fx_impl.rb:119)
org.jruby.RubyProc.call(org/jruby/RubyProc.java:342)
org.jruby.RubyProc.call(org/jruby/RubyProc.java:248)
org.jruby.javasupport.Java$ProcToInterface.callProc(org/jruby/javasupport/Java.java:1029)
org.jruby.javasupport.Java$ProcToInterface.access$200(org/jruby/javasupport/Java.java:1006)
org.jruby.javasupport.Java$ProcToInterface$ConcreteMethod.call(org/jruby/javasupport/Java.java:1067)
com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(com/sun/javafx/application/PlatformImpl.java:326)
com.sun.javafx.application.PlatformImpl.lambda$null$173(com/sun/javafx/application/PlatformImpl.java:295)
java.security.AccessController.doPrivileged(Native Method)
com.sun.javafx.application.PlatformImpl.lambda$runLater$174(com/sun/javafx/application/PlatformImpl.java:294)
com.sun.glass.ui.InvokeLaterDispatcher$Future.run(com/sun/glass/ui/InvokeLaterDispatcher.java:95)
Reverting to normal parsing...

[byteit101]

Know bug. jrubfx-fxmlloader has some caching issues with certain constructs. You can either attempt to debug the current jrubyfx-fxmlloader, which is a pain and very messy, or wait for a clean fix that is dependent upon jruby/jruby#3366 is fixed in jruby