TypeError: 'type' object is not subscriptable when launching rosbridge_websocket

[AlfonGio]

Description Hi, I am trying to launch rosbridge server: rosbridge_websocket to connect ROS2 environment with web interface but this error arise.

• Library Version: ros2 version rosbridge_suite repo
• ROS Version: Foxy
• Platform / OS: Jetson Orin Nano / NVIDIA Jetpack 5 / Ubuntu 20.04

Steps To Reproduce

1. Clone ros2 branch of rosbridge_suite locally
2. Colcon build the rosbridge_suite package
3. Source the workspace
4. Launch the package using ros2 launch rosbridge_server rosbridge_websocket_launch.xml

Expected Behavior The rosbridge_server successfully launched

Actual Behavior [rosapi_node-2] Traceback (most recent call last): [rosapi_node-2] File "/home/orin/workspaces/web_ros-dev/install/rosapi/lib/rosapi/rosapi_node", line 41, in [rosapi_node-2] from rosapi import glob_helper, objectutils, params, proxy [rosapi_node-2] File "/home/orin/workspaces/web_ros-dev/install/rosapi/lib/python3.8/site-packages/rosapi/objectutils.py", line 39, in [rosapi_node-2] from rosbridge_library.internal import ros_loader [rosapi_node-2] File "/home/orin/workspaces/web_ros-dev/install/rosbridge_library/lib/python3.8/site-packages/rosbridge_library/internal/ros_loader.py", line 132, in [rosapi_node-2] typestring: str, intf_type: str, loaded_intfs: dict[str, Any], intf_lock: Lock [rosapi_node-2] TypeError: 'type' object is not subscriptable

[sea-bass]

I suspect that because you're on Foxy (an unsupported ROS 2 version), that uses Python 3.8, type hints recently added to some files are being affected as shown in e.g. this issue:

https://github.com/langchain-ai/langchain/issues/11226#issuecomment-1744288441

Could you try out the fix there to add this to the affected files?

from __future__ import annotations

[AlfonGio]

It should works, the websocket_launch.py can be launched. Thanks.