You can trigger it with a single class that initializes one field with a call to a static method of the same class.
And a second static field that is initialized by performing a computation on the first static field.
Here's a simplified example of the same - https://ashishb.net/programming/java/final-variable-with-two...
There's a number of libraries (particularly around serialization/marshaling) which will end up mutating `final` fields. In fact, this is a trick I've pulled once or twice in my own code for "reasons" (generally needing to modify behavior of a library because it was deficient).
I suspect this will be one of those things that ends up requiring java devs everywhere to bump up the versions of the libraries they use.
There's a jdk.internal API which will work as an escape hatch, but that does come with the need for non-compliant libraries to switch over to it. That safety hatch also only allows the setting of final fields once before observation (which is generally fine). So if your code is doing something more esoteric that sets a final field multiple times you will be SOL.
In any case, if you are using the sun.misc.Unsafe methods for setting final and private fields you'll need to update.
This particularly matters when you have something likes this
class Local {
private final ThirdPartyObject tpo;
}
class Local {
private final LocalDate ld;
}