Fix deprecated Unsafe access (Java 24+)

[Karolina-Bogacka]

Warning text:

WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::objectFieldOffset has been called by scala.runtime.LazyVals$ (file:/home/karokaro/IdeaProjects/cli/target/graalvm-native-image/jelly-cli)
WARNING: Please consider reporting this to the maintainers of class scala.runtime.LazyVals$
WARNING: sun.misc.Unsafe::objectFieldOffset will be removed in a future release

native-image --version

native-image 24 2025-03-18
GraalVM Runtime Environment Oracle GraalVM 24+36.1 (build 24+36-jvmci-b01)
Substrate VM Oracle GraalVM 24+36.1 (build 24+36, serial gc, compressed references)

Context:
The warning does not appear in test output or global artefacts, just in the above local deployment.

[Ostrzyciel]

Yup, stuff was deprecated in Java 24. This will need to be resolved by the scala lib.

[Ostrzyciel]

Upstream issue: https://www.scala-lang.org/news/next-scala-lts-jdk.html

Should be resolved in Scala 3.8: https://www.scala-lang.org/news/next-scala-lts-jdk.html

Until then we can disable it with a JVM option: --sun-misc-unsafe-memory-access=allow

I'd suggest to add it to the Graal options in sbt if it detects that the Scala version is older than 3.8. Otherwise, it will throw an exception. This way we will remember to remove this workaround once Scala fixes it.

[Karolina-Bogacka]

Even though the bugfix seemed to work yesterday, the warning appears again today. No idea why, but reopening issue.

[Ostrzyciel]

are you sure your branch is rebased on main?

[Karolina-Bogacka]

Yes, 100%

[Ostrzyciel]

Was a bad merge issue. 😆 oh well