[BUG] RuntimeError: deque mutated during iteration

[zymouse]

Description

• version: 2.5.0

Error in ros2 subscriber callback function modifying value of ui object

[robobus3_gui-1] Exception in thread Thread-1 (ros_main):
[robobus3_gui-1] Traceback (most recent call last):
[robobus3_gui-1]   File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
[robobus3_gui-1]     self.run()
[robobus3_gui-1]   File "/usr/lib/python3.10/threading.py", line 953, in run
[robobus3_gui-1]     self._target(*self._args, **self._kwargs)
[robobus3_gui-1]   File "/home/nvidia/pix/robobus/autoware-robobus/install/autoware_simplicity_gui/lib/python3.10/site-packages/autoware_simplicity_gui/robobus3_gui.py", line 775, in ros_main
[robobus3_gui-1]     rclpy.spin(node)
[robobus3_gui-1]   File "/opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/__init__.py", line 222, in spin
[robobus3_gui-1]     executor.spin_once()
[robobus3_gui-1]   File "/opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/executors.py", line 739, in spin_once
[robobus3_gui-1]     self._spin_once_impl(timeout_sec)
[robobus3_gui-1]   File "/opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/executors.py", line 736, in _spin_once_impl
[robobus3_gui-1]     raise handler.exception()
[robobus3_gui-1]   File "/opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/task.py", line 239, in __call__
[robobus3_gui-1]     self._handler.send(None)
[robobus3_gui-1]   File "/opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/executors.py", line 437, in handler
[robobus3_gui-1]     await call_coroutine(entity, arg)
[robobus3_gui-1]   File "/opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/executors.py", line 362, in _execute_subscription
[robobus3_gui-1]     await await_or_execute(sub.callback, msg)
[robobus3_gui-1]   File "/opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/executors.py", line 107, in await_or_execute
[robobus3_gui-1]     return callback(*args)
[robobus3_gui-1]   File "/home/nvidia/pix/robobus/autoware-robobus/install/autoware_simplicity_gui/lib/python3.10/site-packages/autoware_simplicity_gui/robobus3_gui.py", line 156, in onOrin2Header
[robobus3_gui-1]     self.label_orin2.text = f"{msg.frame_id}: {msg.stamp.sec}"
[robobus3_gui-1]   File "/home/nvidia/.local/lib/python3.10/site-packages/nicegui/binding.py", line 155, in __set__
[robobus3_gui-1]     self._change_handler(owner, value)
[robobus3_gui-1]   File "/home/nvidia/.local/lib/python3.10/site-packages/nicegui/elements/mixins/text_element.py", line 11, in <lambda>
[robobus3_gui-1]     on_change=lambda sender, text: cast(Self, sender)._handle_text_change(text))  # pylint: disable=protected-access
[robobus3_gui-1]   File "/home/nvidia/.local/lib/python3.10/site-packages/nicegui/elements/mixins/text_element.py", line 85, in _handle_text_change
[robobus3_gui-1]     self.update()
[robobus3_gui-1]   File "/home/nvidia/.local/lib/python3.10/site-packages/nicegui/element.py", line 388, in update
[robobus3_gui-1]     self.client.outbox.enqueue_update(self)
[robobus3_gui-1]   File "/home/nvidia/.local/lib/python3.10/site-packages/nicegui/outbox.py", line 41, in enqueue_update
[robobus3_gui-1]     self._set_enqueue_event()
[robobus3_gui-1]   File "/home/nvidia/.local/lib/python3.10/site-packages/nicegui/outbox.py", line 35, in _set_enqueue_event
[robobus3_gui-1]     self._enqueue_event.set()
[robobus3_gui-1]   File "/usr/lib/python3.10/asyncio/locks.py", line 191, in set
[robobus3_gui-1]     for fut in self._waiters:
[robobus3_gui-1] RuntimeError: deque mutated during iteration

[falkoschindler]

@zymouse Please describe how to reproduce this error. Can you share a minimal reproducible example? Does it help to upgrade to the latest NiceGUI 2.9.1?