Feature org.graalvm.home.HomeFinderFeature class not found

Question

I downloaded the Java/JavaFX source from RubikFX.

I installed GraalVM Java21 from Oracle's site for a Linux Mint 21, amd64 laptop.

In the pom.xml I upped the version of the GluonFX plugin from 1.0.18 to 1.0.21 since using J21.

After setting JAVA_HOME, PATH and GRAALVM_HOME I ran:

mvn javafx:run

and got an error in the log that stating: "launcher.c:28:10: fatal error: stdio.h: No such file or directory"

After a bit of googling, the suggestion was to run:

sudo apt-get install libc6-dev

I then re-ran:

mvn javafx:run

and this time got:

Error: Feature org.graalvm.home.HomeFinderFeature class not found on the classpath. Ensure that the name is correct and that the class is on the classpath.
com.oracle.svm.core.util.UserError$UserException: Feature org.graalvm.home.HomeFinderFeature class not found on the classpath. Ensure that the name is correct and that the class is on the classpath.
    at org.graalvm.nativeimage.builder/com.oracle.svm.core.util.UserError.abort(UserError.java:73)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.FeatureHandler.registerFeatures(FeatureHandler.java:183)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.setupNativeImage(NativeImageGenerator.java:896)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.doRun(NativeImageGenerator.java:590)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.run(NativeImageGenerator.java:550)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.buildImage(NativeImageGeneratorRunner.java:538)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.build(NativeImageGeneratorRunner.java:720)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.start(NativeImageGeneratorRunner.java:142)
    at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.main(NativeImageGeneratorRunner.java:97)

Has anyone else seen this, and know of a solution?

BTW - I am not particularly interested in this specific Java/JavaFX but picked it because I saw the developer had added the JavaFX/GluonFX GraalVM plugins and assumed he'd got things to work, and so wanted to replicate his build. Over the past year or so I've tried numerous times to get the simplest of HelloWorld JavaFX apps to build in GraalVM and never had any success yet. And that luck seems to continue.