rosidl_generator_py error during the building

[AkgunOnur]

Environment

• Operating System: [e.g., Ubuntu 22.04]
• ROS2 Version: Humble
• Python Version: [e.g., 3.10]
• Build Tool: colcon
• Installation type: [e.g., from source, following the official documentation]

Description

I encountered an ImportError when attempting to build the motion_capture_tracking_interfaces

Steps to Reproduce

1. Set up a ROS 2 Humble environment according to the ROS 2 documentation.
2. Create a workspace for motion_capture_tracking_interfaces and clone the repositories into the src directory.
3. Run rosdep install --from-paths src --ignore-src --rosdistro humble -y to install dependencies.
4. Attempt to build the workspace with colcon build.

The build process fails with the following error for the motion_capture_tracking_interfaces package:

--- stderr: motion_capture_tracking_interfaces
Traceback (most recent call last):
File "/opt/ros/humble/share/rosidl_generator_py/cmake/../../../lib/rosidl_generator_py/rosidl_generator_py", line 8, in
from rosidl_generator_py import generate_py
ImportError: cannot import name 'generate_py' from 'rosidl_generator_py' (/opt/ros/humble/local/lib/python3.10/dist-packages/rosidl_generator_py/init.py)
gmake[2]: *** [motion_capture_tracking_interfaces__py/CMakeFiles/motion_capture_tracking_interfaces__py.dir/build.make:155: rosidl_generator_py/motion_capture_tracking_interfaces/_motion_capture_tracking_interfaces_s.ep.rosidl_typesupport_fastrtps_c.c] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:590: motion_capture_tracking_interfaces__py/CMakeFiles/motion_capture_tracking_interfaces__py.dir/all] Error 2
gmake: *** [Makefile:146: all] Error 2

Failed <<< motion_capture_tracking_interfaces [1.54s, exited with code 2]

Additional Context

• I confirmed that my ROS 2 environment is sourced correctly.
• Python dependencies were checked and are all present.
• Similar builds in the same environment for other packages do not encounter this issue.

Any guidance or suggestions to resolve this build error would be greatly appreciated.

[whoenig]

This package is run on the official ROS 2 build farm, see https://build.ros2.org/job/Hdev__motion_capture_tracking__ubuntu_jammy_amd64/lastBuild/, and there are no issues there (apart from warnings that are generated by submodules). We also test via docker on github that the build is fine. Thus, I assume that this is really more a problem with your ROS 2 setup (did you update all your humble packages?).