ros2-package

# ROS 2 Package Creation & Build Wiring (Ubuntu 24.04 LTS & ROS 2 Jazzy) Most "it built fine but doesn't run" bugs are wiring, not code. This skill covers the seams between a source file and a runnable node. ## 1. Documentation Entry Points | For | Entry point | | :--- | :--- | | ament_cmake reference (install, exports, testing hooks) | `https://docs.ros.org/en/jazzy/How-To-Guides/Ament-CMake-Documentation.html` | | Package creation, custom interfaces, colcon tutorials | `https://docs.ros.org/en/jazzy/Tutorials/` | Ground truth beats both: read a working installed package under `/opt/ros/jazzy/share/<pkg>/` and copy its structure. ## 2. The Wiring That Makes a Node Runnable **`ament_cmake`**: executables must install to `lib/${PROJECT_NAME}` exactly — that is the only place `ros2 run` looks. `launch/` and `params/` are not installed by default and need their own `install(DIRECTORY ...)` into `share/${PROJECT_NAME}`. `ament_package()` comes last, exactly once. **`ament_python`**: `package.xml` needs `<export><build_type>ament_python</build_type></export>`, or colcon configures the package as `ament_cmake` and fails looking for a `CMakeLists.txt` that was never meant to exist. `setup.cfg` needs the ROS-specific install location, not just `[metadata]`: ```ini [develop] script_dir=$base/lib/my_package [install] install_scripts=$base/lib/my_package ``` Without it, `console_scripts` still builds and installs, just not to `lib/${PROJECT_NAME}` — the same place `ros2 run` loo...