[gz_ros2_control-system] Could not find shared library

[Juancams]

Hi!

I'm trying to get the tiago robot working inside harmonic with ros 2 jazzy and I'm having the following problem:

[gz-1] [Err] [SystemLoader.cc:92] Failed to load system plugin [gz_ros2_control-system] : Could not find shared library.

This is what I have in my ros2_control.urdf.xacro

...

<!-- Init the ROS 2 control gazebo interface -->
    <xacro:if value="${use_sim_time}">
      <gazebo>
        <plugin name="gz_ros2_control::GazeboSimROS2ControlPlugin" filename="gz_ros2_control-system">
          <parameters>$(find tiago_description)/ros2_control/gazebo_controller_manager_cfg.yaml</parameters>
        </plugin>
      </gazebo>
    </xacro:if>

    <!-- ROS 2 control config-->
    <ros2_control name="ros2_control_tiago_system" type="system">

      <!-- Execution env config -->
      <hardware>
        <xacro:if value="${use_sim_time}">
          <plugin>gz_ros2_control/GazeboSimSystem</plugin>

        <!-- IMU sensor (only in simulation)-->
        <xacro:ros2_control_imu name="base_imu_sensor"/>
        </xacro:if>
        <xacro:unless value="${use_sim_time}">
          <plugin>robot_control/RobotControl</plugin>
        </xacro:unless>
      </hardware>

...

In another simulator that I have in which I use a UR10 I have no problem putting it like that, but here there is no way and I have tried to call it in different ways.

Thank you so much!

[christophfroehlich]

First of all, can you run the gz_ros2_control_demos successfully?

[Juancams]

Yes, they work correctly.

[christophfroehlich]

You should cleanup the part from your snippet, why do you have several plugin tags? Use a clean simple working one from the demos, and put some xacro conditions afterwards if you need them.

[n4495]

I had a similar problem where I could run the gz_ros2_control_demos without issue but when I tried to use my own URDF+launch files GZ threw the "Could not find shared library" error. Even Using the URDF from the examples with my launch script gave the same result. So I assume the problem is in my launch file.

Turns out the shell var GZ_SIM_SYSTEM_PLUGIN_PATH wasn't set so I pointed it to where I found libgz_ros2_control-system.so.

export GZ_SIM_SYSTEM_PLUGIN_PATH=/opt/ros/jazzy/lib/

This worked but I'm still not sure why the example launch has this set and mine does not.

[Amronos]

I also had a similar problem. In my case I think it was caused by using the gz_server.launch.py launch file. The launch file uses gzserver.cpp to just start a gz server. I don't encounter this problem when using the gz_sim.launch.py launch file which the demos use.
I think the plugin path for some reason is not added when using gzserver.cpp.

[roncapat]

I had a similar problem where I could run the gz_ros2_control_demos without issue but when I tried to use my own URDF+launch files GZ threw the "Could not find shared library" error. Even Using the URDF from the examples with my launch script gave the same result. So I assume the problem is in my launch file.

Turns out the shell var GZ_SIM_SYSTEM_PLUGIN_PATH wasn't set so I pointed it to where I found libgz_ros2_control-system.so.

export GZ_SIM_SYSTEM_PLUGIN_PATH=/opt/ros/jazzy/lib/

This worked but I'm still not sure why the example launch has this set and mine does not.

I confirm it works. Thank you @n4495 for sharing your mitigation here.

[siyengar04]

I had a similar problem where I could run the gz_ros2_control_demos without issue but when I tried to use my own URDF+launch files GZ threw the "Could not find shared library" error. Even Using the URDF from the examples with my launch script gave the same result. So I assume the problem is in my launch file.

Turns out the shell var GZ_SIM_SYSTEM_PLUGIN_PATH wasn't set so I pointed it to where I found libgz_ros2_control-system.so.

export GZ_SIM_SYSTEM_PLUGIN_PATH=/opt/ros/jazzy/lib/

This worked but I'm still not sure why the example launch has this set and mine does not.

can confirm, this workaround seems to work for me.