message: action-fuzzer: print a complete backtrace
diff: @@ -1340,7 +1340,9 @@ fn reduce_with_state(action: &ActionWithMeta<Action>) -> bool {
  let prev_hook = std::panic::take_hook();
  std::panic::set_hook(Box::new(move |panic_info| {
  + let bt = std::backtrace::Backtrace::force_capture();
  println!("NEW CRASH {}", panic_info);
  + println!("{:?}", bt);
  }));
  let mut state = FUZZER_STATE.write().unwrap();
  