Invalid joint names

[mhubii]

hello @mhubii I'm having some problems replicating this demo.
It's at https://github.com/lbr-stack/lbr_fri_ros2_stack/blob/humble/lbr_demos/lbr_demos_py/lbr_demos_py/joint_trajectory_client.py
The following error occurs when no modifications are made

[INFO] [1735882172.589733034] [lbr.joint_trajectory_client]: Action server available.
[INFO] [1735882172.590060335] [lbr.joint_trajectory_client]: Rotating odd joints.
[ERROR] [1735882172.591373681] [lbr.joint_trajectory_client]: Goal was rejected by server.
[INFO] [1735882172.591650790] [lbr.joint_trajectory_client]: Moving to zero position.
[ERROR] [1735882172.592469636] [lbr.joint_trajectory_client]: Goal was rejected by server.

At the same time, the following ERROR occurs in the lbr_bringup terminal

[ruby $(which ign) gazebo-3] [ERROR] [1735882172.590616486] [lbr.joint_trajectory_controller]: Incoming joint A1 doesn't match the controller's joints.
[ruby $(which ign) gazebo-3] [INFO] [1735882172.591971219] [lbr.joint_trajectory_controller]: Received new action > goal
[ruby $(which ign) gazebo-3] [ERROR] [1735882172.592006359] [lbr.joint_trajectory_controller]: Incoming joint A1 doesn't match the controller's joints.

In gazebo Entity tree, the joint name is lbr_A1.. So I changed line 38 in the file joint_trajectory_client.py from > joint_trajectory_goal.trajectory.joint_names.append(f"A{i + 1}")
to
joint_trajectory_goal.trajectory.joint_names.append(f"lbr_A{i + 1}")
There are no errors in the lbr_bringup terminal, and the action seemed to be accepted

[ruby $(which ign) gazebo-3] [INFO] [1735882893.824892561] [lbr.joint_trajectory_controller]: Received new action goal
[ruby $(which ign) gazebo-3] [INFO] [1735882893.824969735] [lbr.joint_trajectory_controller]: Accepted new action goal

BUT the following error occurs about two seconds after running again:

[INFO] [1735882893.823955360] [lbr.joint_trajectory_client]: Action server available.
[INFO] [1735882893.824274793] [lbr.joint_trajectory_client]: Rotating odd joints.
[INFO] [1735882893.825519684] [lbr.joint_trajectory_client]: Goal was accepted by server.
Traceback (most recent call last):
 File "/home/u051/lbr-stack/install/lbr_demos_py/lib/lbr_demos_py/joint_trajectory_client", line 33, in <module>
   sys.exit(load_entry_point('lbr-demos-py', 'console_scripts', 'joint_trajectory_client')())
 File "/home/u051/lbr-stack/build/lbr_demos_py/lbr_demos_py/joint_trajectory_client.py", line 73, in main
   joint_trajectory_client.execute(
 File "/home/u051/lbr-stack/build/lbr_demos_py/lbr_demos_py/joint_trajectory_client.py", line 60, in execute
   result_future.result().result.error_code
AttributeError: 'NoneType' object has no attribute 'result'
[ros2run]: Process exited with failure 1

So far I don't know how to solve it, I am indeed very beginner in ros, please forgive my unprofessional description and tell me what to do. thanks!

Originally posted by @BabuBabuDUT in #162 (comment)