What depends on netty-tcnative in Quarkus? - quarkus

Question

This pertains to a GitHub issue where TensorFlow is being loaded at runtime for native image:
https://github.com/awslabs/djl/issues/103#issuecomment-658549779
It causes a io.netty.internal.tcnative.SSLPrivateKeyMethod class not found error during native image compilation. If I add this dependency, the error goes away:
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-tcnative</artifactId>
<version>2.0.31.Final</version>
</dependency>
Here is the stack trace:
Fatal error:java.lang.NoClassDefFoundError
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
at java.base/java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:603)
at java.base/java.util.concurrent.ForkJoinTask.get(ForkJoinTask.java:1006)
at com.oracle.svm.hosted.NativeImageGenerator.run(NativeImageGenerator.java:463)
at com.oracle.svm.hosted.NativeImageGeneratorRunner.buildImage(NativeImageGeneratorRunner.java:359)
at com.oracle.svm.hosted.NativeImageGeneratorRunner.build(NativeImageGeneratorRunner.java:518)
at com.oracle.svm.hosted.NativeImageGeneratorRunner.main(NativeImageGeneratorRunner.java:117)
at com.oracle.svm.hosted.NativeImageGeneratorRunner$JDK9Plus.main(NativeImageGeneratorRunner.java:546)
Caused by: java.lang.NoClassDefFoundError: io/netty/internal/tcnative/SSLPrivateKeyMethod
at jdk.internal.vm.ci/jdk.vm.ci.hotspot.CompilerToVM.getDeclaredMethods(Native Method)
at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotResolvedObjectTypeImpl.getDeclaredMethods(HotSpotResolvedObjectTypeImpl.java:958)
at com.oracle.svm.jni.access.JNIAccessibleMethod.anyMatchIgnoreReturnType(JNIAccessibleMethod.java:139)
at com.oracle.svm.jni.access.JNIAccessibleMember.findHidingSubclasses(JNIAccessibleMember.java:103)
at com.oracle.svm.jni.access.JNIAccessibleMember.findHidingSubclasses(JNIAccessibleMember.java:110)
at com.oracle.svm.jni.access.JNIAccessibleMember.setHidingSubclasses(JNIAccessibleMember.java:83)
at com.oracle.svm.jni.access.JNIAccessibleMethod.finishBeforeCompilation(JNIAccessibleMethod.java:135)
at com.oracle.svm.jni.access.JNIAccessFeature.beforeCompilation(JNIAccessFeature.java:348)
at com.oracle.svm.hosted.NativeImageGenerator.lambda$doRun$2(NativeImageGenerator.java:595)
at com.oracle.svm.hosted.FeatureHandler.forEachFeature(FeatureHandler.java:70)
at com.oracle.svm.hosted.NativeImageGenerator.doRun(NativeImageGenerator.java:595)
at com.oracle.svm.hosted.NativeImageGenerator.lambda$run$0(NativeImageGenerator.java:451)
at java.base/java.util.concurrent.ForkJoinTask$AdaptedRunnableAction.exec(ForkJoinTask.java:1407)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:177)
Caused by: java.lang.ClassNotFoundException: io.netty.internal.tcnative.SSLPrivateKeyMethod
at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 18 more
It is definitely related to one of the following configs, and does also seem to be impacted by JNI, but I am not sure how.
quarkus.native.enable-jni=true
quarkus.ssl.native=true
quarkus.native.additional-build-args=--initialize-at-run-time=org.tensorflow\\,ai.djl\\,org.bytedeco
In searching through the Quarkus GitHub repos, I cannot find reference to netty-tcnative. I really do not understand why this is needed as it seems to be related to Tomcat?
In order to fix this problem, or file a GitHub issue, need to understand where this dependency is expected.