How to debug Java SE 6 using Eclipse 2022-12?

I cannot debug Java SE 6 using Eclipse 2022-12, It throws the following exception:

java.lang.UnsupportedClassVersionError: org/eclipse/jdt/launching/internal/javaagent/Premain : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(Unknown Source)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$000(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(Unknown Source)
    at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(Unknown Source)
FATAL ERROR in native method: processing of -javaagent failed
Exception in thread "main"

However, I can run this project (Java SE 6) without any problem. I can also run and debug another Java SE 7 normally.

It's same as the problem posted here: https://www.eclipse.org/forums/index.php/mv/msg/1112218/1856754/

It's maybe happen since this change: https://github.com/eclipse-jdt/eclipse.jdt.debug/issues/61

So. is there a way to debug Java SE 6 using eclipse 2022-12, thank you.

Solution

TL;DR

Downgrade your Eclipse up to 2022-09
Double check Java version after that

Long story

A colleague had this problem today and after some tinkering we've got it to work. His Eclipse was also stopping at a ghost breakpoint. He had never ever worked on that project and we had cleaned up everything, but even then, it would stop at a breakpoint and break with the mentioned error.

After reading the links in this question, now I understand why this worked, but the second item was very unexpected:

I was on 2022-03 where it was working, so we downgraded his Eclipse to 2022-03 as well. As you pointed out, it seems they have made a change that created this bug during debug mode for Java 1.6.
After that, we double checked Java version everywhere and we found out that the Java 1.6 that was showing up on Eclipse was actually a Java 11 (it was written like "JavaSE-1.6 (jdk 11)"), so we forced it to use from a new Java 1.6 location. I assume Eclipse mixed up something, because I think it runs on Java 11.

After that, debug was working again.