Warning about use of JNI in JDK 24

[basil]

WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by com.sun.jna.Native in an unnamed module (file:/usr/share/java/jna-5.17.0.jar)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

When running with --illegal-native-access=deny (the default in the future):

java.lang.IllegalCallerException: Illegal native access from an unnamed module (file:/var/cache/jenkins/war/WEB-INF/lib/jna-5.17.0.jar)
	at java.base/java.lang.Module.ensureNativeAccess(Module.java:308)
	at java.base/java.lang.System$1.ensureNativeAccess(System.java:2084)
	at java.base/jdk.internal.reflect.Reflection.ensureNativeAccess(Reflection.java:123)
	at java.base/java.lang.System.load(System.java:1623)
	at com.sun.jna.Native.loadNativeDispatchLibraryFromClasspath(Native.java:1041)
	at com.sun.jna.Native.loadNativeDispatchLibrary(Native.java:1011)
	at com.sun.jna.Native.<clinit>(Native.java:221)
Caused: java.lang.ExceptionInInitializerError
	at hudson.lifecycle.SystemdLifecycle$Systemd.<clinit>(SystemdLifecycle.java:26)
	at hudson.lifecycle.SystemdLifecycle.notify(SystemdLifecycle.java:62)
	at hudson.lifecycle.SystemdLifecycle.onExtendTimeout(SystemdLifecycle.java:52)
[…]

Related: https://openjdk.org/jeps/472

[matthiasblaesing]

Thanks for the heads-up. But in the end JNA can't do anything here. This needs to be solved by the users. For JNA itself it is the build process, that is affected. See here: #1666

[basil]

I looked through the documentation in https://github.com/java-native-access/jna/tree/a9db983d2211eab6f073225e3b9ffa82cd00267e/www but I did not see anything about how a user should resolve this issue.

[matthiasblaesing]

The JVM needs to be started with --enable-native-access=ALL-UNNAMED (JNA on classpath) or --enable-native-access=com.sun.jna (JNA on modulepath).

[matthiasblaesing]

Please check the updated javadoc from #1669, this is what I think can be done.

[basil]

Thank you very much!