vcs import fails when cloning ROS 2 repo (MacOS)

Question

I am following the instructions for building ROS 2 (Humble) on MacOS Sonoma 14.5. When I get to the part about cloning the ROS 2 repo, vcs fails with this error:

vcs import --input https://raw.githubusercontent.com/ros2/ros2/humble/ros2.repos src
Traceback (most recent call last):
  File "/Users/ryanolson/ros2env/bin/vcs", line 5, in <module>
    from vcstool.commands.vcs import main
  File "/Users/ryanolson/ros2env/lib/python3.12/site-packages/vcstool/commands/vcs.py", line 3, in <module>
    from vcstool.commands.help import get_entrypoint
  File "/Users/ryanolson/ros2env/lib/python3.12/site-packages/vcstool/commands/help.py", line 4, in <module>
    from pkg_resources import load_entry_point
  File "/Users/ryanolson/ros2env/lib/python3.12/site-packages/pkg_resources/__init__.py", line 2172, in <module>
    register_finder(pkgutil.ImpImporter, find_on_path)
                    ^^^^^^^^^^^^^^^^^^^
AttributeError: module 'pkgutil' has no attribute 'ImpImporter'. Did you mean: 'zipimporter'?

I noticed that the same error happens any time I run vcs (such as vcs -h).

I got vcstool from step 5 in the tutorial (python3 -m pip install -U ...). I am using a custom venv to get around the "externally managed environment" warning from pip.

Llama LLM has suggested that my python version (3.12.4) may be too new for vcstool, but I have not been able to verify that separately. Any suggestions? Thanks

Answer 1

Turns out that vcstool is indeed not compatible with Python 3.12.

The workaround for me was to create a venv with Python 3.9 and install/run vcs from there just to grab the ROS2 source code. I then went back to my ROS venv for the build.