Add JDK 20 support?

[b4sjoo]

Describe the feature
Do you have any timeline in adding support for JDK 20.

Additional context
https://openjdk.org/projects/jdk/20/

Issue:
Right now we need to use JDK 20 to do the gradle build but task delombok failed with following message:

Exception in thread "main" java.lang.NoSuchFieldError: var
	at lombok.delombok.PrettyPrinter.visitForeachLoop(PrettyPrinter.java:1256)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCEnhancedForLoop.accept(JCTree.java:1232)
	at lombok.delombok.PrettyPrinter.print(PrettyPrinter.java:226)
	at lombok.delombok.PrettyPrinter.print(PrettyPrinter.java:240)
	at lombok.delombok.PrettyPrinter.visitBlock(PrettyPrinter.java:1133)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1088)
	at lombok.delombok.PrettyPrinter.print(PrettyPrinter.java:226)
	at lombok.delombok.PrettyPrinter.visitMethodDef(PrettyPrinter.java:857)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:912)
	at lombok.delombok.PrettyPrinter.print(PrettyPrinter.java:226)
	at lombok.delombok.PrettyPrinter.printClassMembers(PrettyPrinter.java:617)
	at lombok.delombok.PrettyPrinter.visitClassDef(PrettyPrinter.java:556)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:810)
	at lombok.delombok.PrettyPrinter.print(PrettyPrinter.java:226)
	at lombok.delombok.PrettyPrinter.visitTopLevel(PrettyPrinter.java:482)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:549)
	at lombok.delombok.DelombokResult.print(DelombokResult.java:74)
	at lombok.delombok.Delombok.delombok(Delombok.java:819)
	at lombok.delombok.Delombok.main(Delombok.java:326)
	at lombok.delombok.DelombokApp.runDirectly(DelombokApp.java:176)
	at lombok.delombok.DelombokApp.runApp(DelombokApp.java:47)
	at lombok.core.Main.go(Main.java:130)
	at lombok.core.Main.main(Main.java:43)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
	at java.base/java.lang.reflect.Method.invoke(Method.java:578)
	at lombok.launch.Main.main(Main.java:46)

> Task :opensearch-ml-plugin:delombok FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':opensearch-ml-plugin:delombok'.
> Process 'command '/opt/java/openjdk-20/bin/java'' finished with non-zero exit value 1

[dhrubo-os]

For the ml-commons repo, when we execute ./gradlew :opensearch-ml-plugin:delombok we see this error for JDK 20.

I executed the same command with JDK 17 and JDK 19.0.2 and didn't find any issue. Command execution was successful.

But for JDK 20.0, we are facing error. Details here

[Frisch12]

Hi @dhrubo-os,

Unfortunately that's an issue for projectlombok itself.
Have a look at these issues in their repository:
projectlombok/lombok#3393
projectlombok/lombok#3353

It seems that it is currently available on the latest snapshots. However, for a release versions there are still some tests failing.

I'm pretty sure we're able to update the Lombok dependency as soon as there is a final release.

Thank you,
Dennis