In the past you could tell the nodes in a test cluster to attach themselves to a waiting debugger on startup by passing the `--debug-server-jvm` option documented here:

https://github.com/elastic/elasticsearch/blob/c0228c73fea5caf279bf7141eabea50813c4528b/TESTING.asciidoc#L383-L390

I think this changed in #92379 and no longer seems to work. In fact I really wanted to attach a debugger to just one of the nodes in the cluster, and I believe #92379 might make this much easier to use (e.g. maybe via a method `LocalNodeSpecBuilder#debuggerPort(int)`). That'd be even better.
test/test-clusters/src/main/java/org/elasticsearch/test/cluster/local/LocalClusterFactory.java
private final Path repoDir;
        private final Path dataDir;
        private final Path logsDir;
        private final Path configDir;
        private final Path tempDir;
        private boolean initialized = false;
        private Process process = null;
        private DistributionDescriptor distributionDescriptor;
        public Node(LocalNodeSpec spec) {
            this.spec = spec;
            this.workingDir = baseWorkingDir.resolve(spec.getCluster().getName()).resolve(spec.getName());
            this.distributionDir = workingDir.resolve("distro"); 
            this.repoDir = baseWorkingDir.resolve("repo");
            this.dataDir = workingDir.resolve("data");
            this.logsDir = workingDir.resolve("logs");
            this.configDir = workingDir.resolve("config");
            this.tempDir = workingDir.resolve("tmp"); 
        }
        public synchronized void start() {
            LOGGER.info("Starting Elasticsearch node '{}'", spec.getName());
            if (initialized == false) {
                LOGGER.info("Creating installation for node '{}' in {}", spec.getName(), workingDir);
                distributionDescriptor = resolveDistribution();
                LOGGER.info("Distribution for node '{}': {}", spec.getName(), distributionDescriptor);
                initializeWorkingDirectory();
                copyExtraJarFiles();
                installPlugins();
                if (spec.getDistributionType() == DistributionType.INTEG_TEST) {
                    installModules();
                }