Consider this trivial command:

java --add-modules=foo.bar.notpresent -version

On mainline (and I could reproduce this only on mainline - works fine on Java 21 and 22) when that command is executed, I get:

Error occurred during initialization of boot layer
java.lang.ExceptionInInitializerError
Caused by: java.lang.RuntimeException: java.lang.IllegalAccessException: symbolic reference class is not accessible: class java.lang.Class, from public Lookup

On Java 21 and 22, I rightly get a FindException:

Error occurred during initialization of boot layer
java.lang.module.FindException: Module foo.bar.notpresent not found

I'm on macos M1, if that matters.