Tried locally, and it works as you described, just several remarks

[cstamas]

1. if you run it with -X there is a point where all the properties are dumped, and I have

[DEBUG] java.vm.version: 21.0.5+11-LTS
[DEBUG] jdk.debug: release
[DEBUG] jib.to-image: foo:bar
[DEBUG] library.jline.path: /home/cstamas/.sdkman/candidates/maven/current/lib/jline-native
[DEBUG] line.separator:

[DEBUG] maven.build.timestamp: 2025-01-07T20:34:09Z

So the property is def there,

2. IMO problem are NOT system properties not pushed (as I proved with my reproducer, they are), but this:
   https://gist.github.com/cstamas/a16ec72621f1a30e442ff04c897aa8c3
   As I see, this jib maven plugin INCLUDES WHOLE Maven 3.9.3? See https://gist.github.com/cstamas/a16ec72621f1a30e442ff04c897aa8c3#file-gistfile1-txt-L34-L62

Edit: ... maven is filtered out in a later step all right. But this is still strange.

[breun]

I just noticed I made a typo in the instructions, because jib.to-image should be jib.to.image. I’ve fixed that now.

[breun]

Maven plugins should ideally specify dependencies on Maven artifacts with scope provided, right? I could open a ticket about that for jib-maven-plugin, but does this explain the behavior we see with Maven 4.0.0-rc-2 of jib.to.image not getting picked up?

[cstamas]

Well, user properties ARE pushed to Java System Properties, as my reproducer proves: https://github.com/cstamas/MNG-8486

So this is something else... and no, actual classpath does NOT contain 3.9.3, as Maven Core filters that out...

[cstamas]

Mystery solved, commented on https://issues.apache.org/jira/browse/MNG-8486

tldr: please report this as a google jib bug.

[breun]

@cstamas Thanks, I've created a Jib issue for this: GoogleContainerTools/jib#4344