FULL PRODUCT VERSION :
java version "9.0.1"
Java(TM) SE Runtime Environment (build 9.0.1+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.1+11, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Ubuntu 16.04.3 LTS
Linux dell-virtual-machine 4.13.0-26-generic #29~16.04.2-Ubuntu SMP Tue Jan 9 22:00:44 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux


EXTRA RELEVANT SYSTEM CONFIGURATION :
Gradle 4.3
------------------------------------------------------------

Build time: 2017-10-30 15:43:29 UTC
Revision: c684c202534c4138b51033b52d871939b8d38d72

Groovy: 2.4.12
Ant: Apache Ant(TM) version 1.9.6 compiled on June 29 2015
JVM: 9.0.1 (Oracle Corporation 9.0.1+11)
OS: Linux 4.13.0-26-generic amd64


A DESCRIPTION OF THE PROBLEM :
Currently use Arm java8 from Oracle and compile Openjfx for Arm and overlay libraries for current product line. Looking to test Java9 on Arm and upgrade product line in next generation release.

Cross Compiling openJdk9 for Arm works fine

Trying to compile openJfx from http://hg.openjdk.java.net/openjfx/jfx-dev/rt
Running gradle -PCOMPILE_TARGETS=armv6hf produces swing errors even though COMPILE_SWING is false in build.gradle.

Problem seems to be with build.gradle line 2154 which has swing tasks being disabled if COMPILE_SWING is false. This code is commented out.

/* should not be built, but needed in JMX
    tasks.all {
        if (!COMPILE_SWING) it.enabled = false
    }
   */

if I uncomment it these errors go away and the build completes.

The resulting armv6hf-modular-sdk folder created by the build is added to jdk configure script with '-with-import-modules=' option as per build instructions.
Building the jdk now fails with java.base module FindException, are these 2 problems related?



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Followed insturctions

https://wiki.openjdk.java.net/display/OpenJFX/Building+OpenJFX#BuildingOpenJFX-Ubuntu16.04

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Full JVM produced for Arm which includes JavaFX support
ACTUAL -
Failed builds

ERROR MESSAGES/STACK TRACES THAT OCCUR :

<Building OpenJfx error message>
Task :swing:compileJava FAILED
/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/module-info.java:36: error: file should be on source path, or on patch path for module
module javafx.swing {

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/com/sun/javafx/embed/swing/SwingNodeHelper.java:26: error: file should be on source path, or on patch path for module
package com.sun.javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/com/sun/javafx/embed/swing/Disposer.java:26: error: file should be on source path, or on patch path for module
package com.sun.javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/com/sun/javafx/embed/swing/SwingFXUtilsImpl.java:26: error: file should be on source path, or on patch path for module
package com.sun.javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/com/sun/javafx/embed/swing/DisposerRecord.java:26: error: file should be on source path, or on patch path for module
package com.sun.javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/SwingFXUtils.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/FXDnD.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/InputMethodSupport.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/JFXPanel.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/CachingTransferable.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/SwingCursors.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/DataFlavorUtils.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/SwingEvents.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/SwingDnD.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/SwingNode.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

/home/dell/Documents/IwOpenJdk9/src/openjfx/rt/modules/javafx.swing/src/main/java/javafx/embed/swing/SwingDragSource.java:26: error: file should be on source path, or on patch path for module
package javafx.embed.swing;

16 errors

FAILURE: Build failed with an exception.
</Building OpenJfx error message>





<Linking OpenJfx into openJdk build error message>
Error: Module javafx.base not found
java.lang.module.FindException: Module javafx.base not found
at java.base/java.lang.module.Resolver.findFail(Resolver.java:889)
at java.base/java.lang.module.Resolver.resolve(Resolver.java:128)
at java.base/java.lang.module.Configuration.resolve(Configuration.java:357)
at java.base/java.lang.module.Configuration.resolve(Configuration.java:187)
at jdk.jlink/jdk.tools.jlink.internal.Jlink$JlinkConfiguration.resolve(Jlink.java:242)
at jdk.jlink/jdk.tools.jlink.internal.JlinkTask.createImageProvider(JlinkTask.java:439)
at jdk.jlink/jdk.tools.jlink.internal.JlinkTask.createImage(JlinkTask.java:386)
at jdk.jlink/jdk.tools.jlink.internal.JlinkTask.run(JlinkTask.java:263)
at jdk.jlink/jdk.tools.jlink.internal.Main.run(Main.java:54)
at jdk.jlink/jdk.tools.jlink.internal.Main.main(Main.java:33)
make3: *** [/home/dell/Documents/IwOpenJdk9/src/jdk9dev/build/linux-arm-normal-client-release/images/jre/bin/java] Error 1
Images.gmk:144: recipe for target '/home/dell/Documents/IwOpenJdk9/src/jdk9dev/build/linux-arm-normal-client-release/images/jre/bin/java' failed
</Linking OpenJfx into openJdk build error message>


REPRODUCIBILITY :
This bug can be reproduced always.