Main.java

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Main {

    static {
    	System.out.println("here we go...");	
        try (ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor()) {
            executor.submit(() -> {}).get();
        } catch (Exception e) {
            e.printStackTrace();
        }
        
    	System.out.println("...fiuuu!");
    }

    public static void main(String[] args) {
        
    }
}

Run me on Java 21 with:

java Main.java

and it never completes

What fun. I seem to have reproduced the bug here. I'll look later today

break-it Franz, that's my second name :D

So a class loader deadlock, which, by turning the runnable lambda into a proper anonymous class, won't happen anymore...

eg

    static {
    	System.out.println("here we go...");	
        try (ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor()) {
            executor.submit(new Runnable() {
            
              public void run() {
              }
            }).get();
        } catch (Exception e) {
            e.printStackTrace();
        }
        
    	System.out.println("...fiuuu!");
    }

Might not happen any more. Your bullet, your gun, your foot.

...and all the fun, ihih