To reproduce this:

1. set your JAVA_HOME and PATH to point to an OpenJDK 10 build

2. build the JavaFX exports.zip for importing into a JDK build

$ gradle jdkZip

3. configure your local JDK build using "--with-import-modules=$JFX_ROOT/rt/build/javafx-exports.zip"

4. Build your JDK

It will fail with the following error:

Compiling 1 files for javafx.graphics
./build/linux-x86_64-normal-server-release/configure-support/import-modules/modules_src/javafx.graphics/module-info.java:76: warning: [module] module not found: jdk.packager
        jdk.packager;
           ^
error: warnings found and -Werror specified
1 error

This is due to the fix for JDK-8198329. In general, we use an Oracle JDK build to build FX for inclusion into the JDK, and use an OpenJDK for building standalone modules.

However, the intention was that a build of FX with OpenJDK would still produce bits that could be imported into a JDK build, even though that is no longer the primary mode of operation.

This now fails because of a qualified export from javafx.graphics to the no-longer-built jdk.packager module.