[Bug Report] No module named 'rclpy._rclpy_pybind11'

[agrotrushant]

Describe the bug

I am using the container workflow in IsaacLab 2.2 (main branch) and am using ros2 profile but seems like rcpy with pybind11 has some issue.

Steps to reproduce

Clone the IsaacLab repo

git clone git@github.com:isaac-sim/IsaacLab.git
cd IsaacLab

Build ros2 profile container

./docker/container.py start ros2

Launch IsaacSim 5.0

runapp # alias mentioned in ~/.bashrc

I am getting following error:

[29.612s] [ext: isaacsim.ros2.bridge-4.9.3] startup
[29.681s] Attempting to load system rclpy
[29.756s] Could not import system rclpy: No module named 'rclpy._rclpy_pybind11'
The C extension '/opt/ros/humble/lib/python3.10/site-packages/_rclpy_pybind11.cpython-311-x86_64-linux-gnu.so' isn't present on the system. Please refer to 'https://docs.ros.org/en/humble/Guides/Installation-Troubleshooting.html#import-failing-without-library-present-on-the-system' for possible solutions
[29.756s] Attempting to load internal rclpy for ROS Distro: humble
[29.757s] Could not import internal rclpy: No module named 'rclpy._rclpy_pybind11'
The C extension '/opt/ros/humble/lib/python3.10/site-packages/_rclpy_pybind11.cpython-311-x86_64-linux-gnu.so' isn't present on the system. Please refer to 'https://docs.ros.org/en/humble/Guides/Installation-Troubleshooting.html#import-failing-without-library-present-on-the-system' for possible solutions
[29.757s] To use the internal libraries included with the extension please set the following environment variables to use with FastDDS (default) or CycloneDDS before starting Isaac Sim:

FastDDS (default):
export ROS_DISTRO=humble
export RMW_IMPLEMENTATION=rmw_fastrtps_cpp
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/humble/lib

OR

CycloneDDS:
export ROS_DISTRO=humble
export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/humble/lib


2025-08-08T21:02:31Z [29,727ms] [Warning] [humble.rclpy] Could not import rclpy

System Info

Describe the characteristic of your environment:

• Commit: [e.g. 8f3b9ca]
• Isaac Sim Version: 5.0.0
• OS: Ubuntu 22.04
• GPU: RTX Pro 6000 Blackwell
• CUDA: 12.8
• GPU Driver: 570.169

Checklist

• I have checked that there is no similar issue in the repo (required)
• I have checked that the issue is not in running Isaac Sim itself and is related to the repo

Acceptance Criteria

Add the criteria for which this task is considered done. If not known at issue creation time, you can add this once the issue is assigned.

• It should use built ros-base

[RandomOakForest]

Thank you for posting this. We will look into it.

[kimtaehyeong99]

We are experiencing a similar error and would like to resolve it as well.

Here are the details in bug report format for reference:

[bug] rclpy import error due to Python version mismatch (ROS 2 Jazzy vs Isaac Sim)

Describe the bug

We encounter an error when trying to import rclpy while using IsaacLab 2.2 (main branch) together with Isaac Sim 5.0.0 and ROS 2 Jazzy.

The issue seems to be caused by a Python version mismatch:

• ROS 2 Jazzy uses Python 3.12
• Isaac Sim 5.0.0 uses Python 3.11

Because of this, the _rclpy_pybind11 extension cannot be imported correctly.

Steps to reproduce

1. Set up Ubuntu 24.04 with ROS 2 Jazzy.
2. Create a local Python virtual environment.
3. Clone Isaac Sim and Isaac Lab repositories and build them.
4. Try to run IsaacLab with import rclpy.

Error output:

[26.663s] Simulation App Startup Complete
Traceback (most recent call last):
  File "/home/robotis-ai/new_isaaclab/robotis_lab/scripts/tools/record_demos.py", line 97, in <module>
    from ros2_bridge.omy_teleop import OMYLeaderTeleop
  File "/home/robotis-ai/new_isaaclab/robotis_lab/scripts/tools/ros2_bridge/omy_teleop.py", line 1, in <module>
    import rclpy
  File "/opt/ros/jazzy/lib/python3.12/site-packages/rclpy/__init__.py", line 49, in <module>
    from rclpy.signals import install_signal_handlers
  File "/opt/ros/jazzy/lib/python3.12/site-packages/rclpy/signals.py", line 15, in <module>
    from rclpy.exceptions import InvalidHandle
  File "/opt/ros/jazzy/lib/python3.12/site-packages/rclpy/exceptions.py", line 16, in <module>
    from rclpy.impl.implementation_singleton import rclpy_implementation as _rclpy
  File "/opt/ros/jazzy/lib/python3.12/site-packages/rclpy/impl/implementation_singleton.py", line 32, in <module>
    rclpy_implementation = import_c_library('._rclpy_pybind11', package)
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/ros/jazzy/lib/python3.12/site-packages/rpyutils/import_c_library.py", line 39, in import_c_library
    return importlib.import_module(name, package=package)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/robotis-ai/.pyenv/versions/3.11.9/lib/python3.11/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ModuleNotFoundError: No module named 'rclpy._rclpy_pybind11'
The C extension '/opt/ros/jazzy/lib/python3.12/site-packages/_rclpy_pybind11.cpython-311-x86_64-linux-gnu.so' isn't present on the system. Please refer to 'https://docs.ros.org/en/jazzy/How-To-Guides/Installation-Troubleshooting.html#import-failing-without-library-present-on-the-system' for possible solutions

System Info

Describe the characteristic of your environment:

• Commit: 5ca0c32
• Isaac Sim Version: 5.0.0
• OS: Ubuntu 24.04
• GPU: RTX 5090
• CUDA: 12.8
• GPU Driver: 570.133.20

[camopel]

you can try the ROS i build for python 3.11, it works with sim 5.0, this build only support rclpy, not ros cli. which i will release soon https://github.com/camopel/isaacsim-ros2-python3.11

[ashwinvkNV]

I have also built rclpy from source and was able to use it with IsaacLab in the past.

colcon build --packages-up-to rclpy sensor_msgs --cmake-args -DPython3_EXECUTABLE=<local_path_to_isaac_sim>/kit/python/bin/python3 -DCMAKE_BUILD_TYPE=Release

[dxyy1]

I am running into the same issue too. Is there an official patch for this problem, or does it require rebuildiing ros2 altogether?

[chugunovyar]

So, there is no chance to install at ubuntu software from deb ? How you made release ? I can`t run software at any of versions. There always some problems which not allow to do it.

Have any one versions list of software and OS at which with garanty it running and works fine ? Documentation not helps also not have any buttons to riase bug or error.

Накипело ! Извините.

[Benzales]

Are there any updates with this bug? I'm experiencing the exact same issue. I'm seeing the Isaac Sim doc that specifies the need to run custom ROS 2 packages with build based on Python 3.11. However, I don't see a trivial linkage of that to the Isaac Lab deployment.
Doc: Enabling rclpy, Custom ROS 2 Packages, and Workspaces with Python 3.11

[dxyy1]

I managed to circumvent this issue by downgrading isaaclab to the version that is compatible with isaacsim 4.5.0 (isaaclab tag v2.1.1 I think).

[bsplonka]

I have the same issue and I am pretty sure, that it is caused by a mismatch of Python version, seeing, that everything is built with Python 3.12 but pybinds expected version is 3.11. However I don’t know yet how to fix it

[liuquangao]

Please See: https://docs.isaacsim.omniverse.nvidia.com/5.1.0/installation/install_ros.html#isaac-ros-workspace

[HJGrant]

I have the same issue. I am following this Docker guide in the IsaacLab docs. I was not able to build the ROS2 image before downgrading my base image to IsaacSim version 5.0.0 in the .env.base file.
Now it's built, but I am getting the same error as above.

[HJGrant]

I found a note about this in the release note. Apparently it is a known issue with Isaac Lab v2.3.0

[therobocademy]

I tried running Isaac Lab 2.3.1 using Docker, and it throws errors related to ROS 2. The main issue is that the Docker setup installs ROS 2 Humble, while the base image is Ubuntu 24.04.

I created a PR to address this:
#4471

The fix switches the installation to ROS 2 Jazzy. However, there is still a Python 3.12–related issue, specifically with rclpy.

Interestingly, when I publish a topic from Isaac Sim, it appears correctly in the ROS 2 CLI, and image messages are also working. So even though the error is present in the latest setup, the communication seems to function. I’m not entirely sure why this works despite the error.