COL-1002 ros2 test_error ai_generated true

ModuleNotFoundError: No module named 'my_package' during colcon test

ID: ros2/colcon-test-import-error-pkg-name

Also available as: JSON · Markdown · 中文
88%Fix Rate
87%Confidence
1Evidence
2023-11-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
ROS2 Foxy Fitzroy active — — —
ROS2 Galactic Geochelone active — — —
ROS2 Humble Hawksbill active — — —

Root Cause

The Python package name in setup.py or setup.cfg does not match the actual directory name, or the package is not installed in the Python environment due to missing --symlink-install or build path issues.

generic

中文

setup.py 或 setup.cfg 中的 Python 包名称与实际目录名称不匹配，或者由于缺少 --symlink-install 或构建路径问题，包未安装到 Python 环境中。

Official Documentation

https://docs.ros.org/en/humble/Tutorials/Basic/Colcon-Tutorial.html

Workarounds

  1. 90% success Ensure the Python package name in setup.py matches the directory name. For example, if your package directory is 'my_package', set `name='my_package'` in setup.py. Then rebuild with `colcon build --symlink-install` and run tests with `colcon test --packages-select my_package`. 
    Ensure the Python package name in setup.py matches the directory name. For example, if your package directory is 'my_package', set `name='my_package'` in setup.py. Then rebuild with `colcon build --symlink-install` and run tests with `colcon test --packages-select my_package`.
  2. 85% success If using ament_python, verify that the `entry_points` in setup.py are correct and that the test directory has an `__init__.py` file. Run `colcon test --event-handlers console_direct+` to see the full error trace. 
    If using ament_python, verify that the `entry_points` in setup.py are correct and that the test directory has an `__init__.py` file. Run `colcon test --event-handlers console_direct+` to see the full error trace.

中文步骤

  1. Ensure the Python package name in setup.py matches the directory name. For example, if your package directory is 'my_package', set `name='my_package'` in setup.py. Then rebuild with `colcon build --symlink-install` and run tests with `colcon test --packages-select my_package`.
  2. If using ament_python, verify that the `entry_points` in setup.py are correct and that the test directory has an `__init__.py` file. Run `colcon test --event-handlers console_direct+` to see the full error trace.

Dead Ends

Common approaches that don't work:

  1. 50% fail

    Running pip install -e . in the package root may install it temporarily, but colcon will overwrite it on next build, and it doesn't fix the root cause.

  2. 30% fail

    Deleting the entire build directory and rebuilding is overkill; the issue is usually a configuration mismatch, not a corrupted build.