The maven publishing task produces the following gradle deprecation warning.

$ gradle --warning-mode=all sdk
...
As part of making the publishing plugins stable, the 'deferred configurable' behavior of the 'publishing {}' block is now deprecated. Please add 'enableFeaturePreview('STABLE_PUBLISHING')' to your settings file and do a test run by publishing to a local repository. If all artifacts are published as expected, there is nothing else to do. If the published artifacts change unexpectedly, please see the migration guide for more details: https://docs.gradle.org/4.8/userguide/publishing_maven.html#publishing_maven:deferred_configuration. In Gradle 5.0 the flag will be removed and the new behavior will become the default.
        at build_61v2cahy4344a9o4ddauip62l.addMavenPublication(jfx-dev/rt/build.gradle:1511)
        (Run with --stacktrace to get the full stack trace of this deprecation warning.)


This should be fixed in openjfx12 to avoid any surprises if we upgrade to gradle 5.0 in the future.