colcon
I should really understand how colcon works. Not should, HAVE TO.
How are you going to contribute to code at NVIDIA if you don’t even know how colcon works.
Resources
A good exercise for this is building ROS2 from source, and actually seeing what is happening under the hood. Brian Chen did this https://chenbrian.ca/posts/ros2_m1/#8-patch-python_cmake_module on his M1 Mac, so you should learn from him.
Things that are done
- Initialization: Initializes the build environment.
- Package Discovery: Identifies and orders packages based on dependencies.
- Build Execution: Builds each package using its build system.
- Environment Setup: Sets up the environment for built packages.
Colcon vs. CMake?
CMake only works for C++, whereas Colcon works for other languages like Python and rust.
colcon test
Learned from ashwin at NVIDIA.
colcon test --packages-select PACKAGE_NAME
Then, if there is an error, you can do
colcon test-result --verbose
From WATO monorepo:
Running Tests: colcon test
- Runs all tests defined in the CMakeLists.txt for the package including the linter
- Running the following outputs a detailed summary to the console
colcon test --event-handlers console_cohesion+Viewing Test Failures: colcon test-result --verbose
- Generates a detailed summary of failing tests including log statements
Running Tests Until Failure: colcon test --retest-until-fail <N>
- Runs the test suite either N times or until a failure is detected
- Useful for identifying flaky tests and debugging race conditions