HI,
I am doing the topics project in ROS2 python course. But, the following error happens when I try to subscribe to the /scan or publish in /cmd_vel:
user:~/ros2_ws$ ros2 launch wall_follower start_wall_following.launch.py
[INFO] [launch]: All log files can be found below /home/user/.ros/log/2023-05-09-21-10-12-024513-2_xterm-24267
[INFO] [launch]: Default logging verbosity is set to INFO
[INFO] [wall_following_node-1]: process started with pid [24318]
[wall_following_node-1] Traceback (most recent call last):
[wall_following_node-1] File “/home/user/ros2_ws/install/wall_follower/lib/wall_follower/wall_following_node”, line 33, in
[wall_following_node-1] sys.exit(load_entry_point(‘wall-follower==0.0.0’, ‘console_scripts’, ‘wall_following_node’)())
[wall_following_node-1] File “/home/user/ros2_ws/install/wall_follower/lib/python3.8/site-packages/wall_follower/wall_following.py”, line 92, in main
[wall_following_node-1] wall_following_node = WallFollowing()
[wall_following_node-1] File “/home/user/ros2_ws/install/wall_follower/lib/python3.8/site-packages/wall_follower/wall_following.py”, line 19, in init
[wall_following_node-1] self.publisher_ = self.create_publisher(Twist, ‘cmd_vel’, 2)
[wall_following_node-1] File “/opt/ros/foxy/lib/python3.8/site-packages/rclpy/node.py”, line 1140, increate_publisher
[wall_following_node-1] check_for_type_support(msg_type)
[wall_following_node-1] File “/opt/ros/foxy/lib/python3.8/site-packages/rclpy/type_support.py”, line 20, in check_for_type_support
[wall_following_node-1] ts = msg_type.class._TYPE_SUPPORT
[wall_following_node-1] AttributeError: type object ‘type’ has no attribute ‘_TYPE_SUPPORT’ This might be a ROS 1 message type but it should be a ROS 2 message type. Make sure to source your ROS 2 workspace after your ROS 1 workspace.
[ERROR] [wall_following_node-1]: process has died [pid 24318, exit code 1, cmd ‘/home/user/ros2_ws/install/wall_follower/lib/wall_follower/wall_following_node --ros-args’].
The ROS1 is sourced first, then the ROS2. The topics can be viewed using ROS1 and ROS2 command line instructions, but when running the python scripts it does not work.
Please help,
Thanks.