Position actuators not registering as position actuators and yields errors about missing PIDs?

[sea-bass]

Describe the bug
It seems like there is an issue parsing models with position actuators in the latest version of this repo, because I am getting errors about velocity/motor actuators even though I do not have them.

To Reproduce
I had a working model on an older branch of this repo, with actuators formatted as such:

  <actuator>
    <position
      class="Rotation"
      name="shoulder_pan_joint"
      joint="shoulder_pan_joint"
      inheritrange="1"
    />
    <position
      class="Pitch"
      name="shoulder_lift_joint"
      joint="shoulder_lift_joint"
      inheritrange="1"
    />
    <position
      class="Elbow"
      name="elbow_joint"
      joint="elbow_joint"
      inheritrange="1"
    />
    <position
      class="Wrist_Pitch"
      name="wrist_pitch_joint"
      joint="wrist_pitch_joint"
      inheritrange="1"
    />
    <position
      class="Wrist_Roll"
      name="wrist_roll_joint"
      joint="wrist_roll_joint"
      inheritrange="1"
    />
    <position class="Jaw" name="jaw_joint" joint="jaw_joint" inheritrange="1" />
  </actuator>

After upgrading, I get this error:

[ros2_control_node-1] [ERROR] [1767018915.233158717] [MujocoSystemInterface]:
Position command interface for the joint : 
shoulder_pan_joint is not supported with velocity or motor actuator without defining the PIDs

However, these actuators are position actuators, not velocity or motor?

You can get this by:

1. Getting the latest branch of https://github.com/JafarAbdi/ros2_so_arm100
2. Fixing the issue highlighted in Mujoco model parameter susceptible to leading and trailing whitespaces in XML #53
3. Running ros2 launch so_arm100_description controllers_bringup.launch.py hardware_type:=mujoco

If you just want to see the model, it's here: https://github.com/JafarAbdi/ros2_so_arm100/blob/e62f90672ec17a255ab4f9854eefe1fb41df54bf/so_arm100_description/mjcf/so_arm100.xml#L142-L174

Expected behavior
Actuators should be treated as position actuators and this error should not be there. I suspect there is a bug in this getActuatorType function that was recently added, which is looking for the existence of specific bias parameters?

Environment (please complete the following information):

• OS: Ubuntu 24.04
• Version: Kilted

[sea-bass]

OK I have no idea what I just did... but I blew away my build/ and install/ folders, got the latest main, and it seems to work again?

[saikishor]

@sea-bass I'm quite sure this should work. We have tests for both the cases. Let's keep an eye if this happens again, so I can take a look

[eholum-nasa]

Chalking this off as the mysteries of colcon! Let us know if it becomes a problem again...