Plugin not loading correctly in ROS 2 Kilted

[sea-bass]

Describe the bug
I was able to build this package in ROS 2 Kilted but get a runtime error / failure to load the mujoco library at runtime.

To Reproduce
Steps to reproduce the behavior:

1. Clone this repo
2. After rosdep install, run colcon build -- builds fine
3. Run the example: ros2 launch mujoco_ros2_simulation test_robot.launch.py

[ros2_control_node-2] [ERROR] [1764428272.472141404] [controller_manager]: 
Caught exception of type : N9pluginlib20LibraryLoadExceptionE while loading hardware: 
Failed to load library /home/sebastian/workspace/mujoco_ros_ws/install/mujoco_ros2_simulation/lib/mujoco_ros2_simulation/libmujoco_ros2_simulation.so. 
Make sure that you are calling the PLUGINLIB_EXPORT_CLASS macro in the library code, and that names are consistent between this macro and your XML. 
Error string: Could not load library dlopen error: libmujoco.so.3.3.4: cannot open shared object file: 
No such file or directory, at ./src/shared_library.c:96

Expected behavior
Should work

Screenshots
If applicable, add screenshots to help explain your problem.

Environment (please complete the following information):

• OS: Ubuntu 24.04
• Version: ROS 2 Kilted

I can confirm that I have this file auto-fetched and installed:

mujoco_ros2_simulation/mujoco/mujoco-3.3.4/lib/libmujoco.so.3.3.4

And I can ldd it just fine:

$ ldd mujoco/mujoco-3.3.4/lib/libmujoco.so.3.3.4
        linux-vdso.so.1 (0x000074f907256000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x000074f90724b000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x000074f906cf1000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x000074f906a00000)
        /lib64/ld-linux-x86-64.so.2 (0x000074f907258000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x000074f907244000)

[sea-bass]

FYI the unit test test_plugin.cpp also fails with the same error on my machine.

[sea-bass]

OK so I have this:

$ ldd /home/sebastian/workspace/mujoco_ros_ws/install/mujoco_ros2_simulation/lib/mujoco_ros2_simulation/libmujoco_ros2_simulation.so
        linux-vdso.so.1 (0x00007363f3a34000)
        libmujoco.so.3.3.4 => not found   # <-- NOTE: not found!!
        ...  # everything else is found fine

If I manually append the path to my mujoco_ros2_simulation/mujoco/mujoco-3.3.4/lib/libmujoco.so.3.3.4 to LD_LIBRARY_PATH, I can get things to work... but unsure why I need to do it manually.

[saikishor]

Did you source your workspace before launching?. I agree that LD_LIBRARY_PATH should be updated automatically

Hopefully, these kind of issues, will be solved with #6

[sea-bass]

I for sure sourced my workspace!

[saikishor]

I'm trying to download the kilted docker for last 15-20 min and it doesn't allow me LOL. I've timeout issues, once I have it I'll give it a shot

[saikishor]

On a clean kilted docker, I've the issue with the PATH

           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/ros/kilted/lib/python3.12/site-packages/launch/substitutions/find_executable.py", line 66, in perform
    raise SubstitutionFailure("executable '{}' not found on the PATH".format(self.name))
launch.substitutions.substitution_failure.SubstitutionFailure: executable '[<launch.substitutions.text_substitution.TextSubstitution object at 0x7fee8ac36720>]' not found on the PATH

[ERROR] [launch]: Caught exception in launch (see debug for traceback): executable '[<launch.substitutions.text_substitution.TextSubstitution object at 0x7fee8ac36720>]' not found on the PATH
[DEBUG] [launch.launch_context]: emitting event: 'launch.events.Shutdown'
[DEBUG] [launch]: processing event: '<launch.events.shutdown.Shutdown object at 0x7fee92934980>'
[DEBUG] [launch]: processing event: '<launch.events.shutdown.Shutdown object at 0x7fee92934980>' ✓ '<launch.event_handlers.on_shutdown.OnShutdown object at 0x7fee92936bd0>'

[sea-bass]

ah that seems because xacro is just a test_depend and maybe it wasn't installed... (I could repro your error by uninstalling that on my end)

if you do sudo apt install ros-kilted-xacro and try again, does it work?

[saikishor]

Not really, it was installed on my Docker. I'm using the ros:kilted-perception Docker

[eholum-nasa]

This has to be a dumb issue with the FetchContent path that I threw in as a final fallback for building the drivers...
The CMAKE_INSTALL_RPATH_USE_LINK_PATH macro here works with the first two paths but I guess there's a bug if the library is downloaded to the source directory. We probably just need to tweak that to make sure that the path is available after the fact...

That said I think @saikishor is right that the ultimate solution is the vendor package.

[sea-bass]

I can add as a datapoint that I did not clone this repo directly to the src folder of my workspace. It is one level down. So like:

ws/src/main_repo/mujoco_ros2_simulation

Could that be it?

[eholum-nasa]

Can you give this a shot #14?