I am having trouble building the packages

[maciejmajek]

Using virtual environments with ROS 2 can sometimes be a bit of a hassle.
If you are having problems building rai or running packages, take a look at the following thread.

[maciejmajek]

ModuleNotFoundError: No module named 'em'

  Traceback (most recent call last):

    File "<frozen runpy>", line 198, in _run_module_as_main
    File "<frozen runpy>", line 88, in _run_code
    File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/__main__.py", line 19, in <module>
      sys.exit(main())
               ^^^^^^
    File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/main.py", line 53, in main
      abs_idl_file = convert_to_idl(
                     ^^^^^^^^^^^^^^^
    File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/__init__.py", line 23, in convert_to_idl
      from rosidl_adapter.srv import convert_srv_to_idl
    File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/srv/__init__.py", line 16, in <module>
      from rosidl_adapter.resource import expand_template
    File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/resource/__init__.py", line 19, in <module>
      import em

  ModuleNotFoundError: No module named 'em'

Details

CMake Error at /opt/ros/jazzy/share/rosidl_adapter/cmake/rosidl_adapt_interfaces.cmake:57 (message):

execute_process(/home/mmajek/.cache/pypoetry/virtualenvs/rai-qH6Oly3A-py3.12/bin/python3
-m rosidl_adapter --package-name rai_interfaces --arguments-file
/home/mmajek/projects/internal/rai/build/rai_interfaces/rosidl_adapter__arguments__rai_interfaces.json
--output-dir
/home/mmajek/projects/internal/rai/build/rai_interfaces/rosidl_adapter/rai_interfaces
--output-file
/home/mmajek/projects/internal/rai/build/rai_interfaces/rosidl_adapter/rai_interfaces.idls)
returned error code 1:

Traceback (most recent call last):

File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/__main__.py", line 19, in <module>
  sys.exit(main())
           ^^^^^^
File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/main.py", line 53, in main
  abs_idl_file = convert_to_idl(
                 ^^^^^^^^^^^^^^^
File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/__init__.py", line 23, in convert_to_idl
  from rosidl_adapter.srv import convert_srv_to_idl
File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/srv/__init__.py", line 16, in <module>
  from rosidl_adapter.resource import expand_template
File "/opt/ros/jazzy/lib/python3.12/site-packages/rosidl_adapter/resource/__init__.py", line 19, in <module>
  import em

ModuleNotFoundError: No module named 'em'

Call Stack (most recent call first):
/opt/ros/jazzy/share/rosidl_cmake/cmake/rosidl_generate_interfaces.cmake:132 (rosidl_adapt_interfaces)
CMakeLists.txt:19 (rosidl_generate_interfaces)

Solution:

1. Deactivate the poetry shell

exit # or ctrl + d

2. Remove the build and install directories

rm -rf build/ install/

3. Build again

colcon build

[maciejmajek]

ModuleNotFoundError: No module named '*'

If you encounter this error during running a ROS 2 command like ros2 run or ros2 launch, you are most likely in a semi-sourced shell.

Solution:

source setup_shell.sh