Developing with Pixi

Pixi builds Aerostack2 straight from a clone of the repository, with ROS 2 from RoboStack and no system-wide install. It's the only way to work on Aerostack2 on macOS, and it works the same on Linux. This page covers the loop of building, changing and running your code.

Before you start

• Pixi 0.83 or later. See Install Pixi.
• A clone of Aerostack2. Clone your fork if you plan to open a pull request, as Opening a pull request explains.
• The git hooks. Install them once, as in Setting up.

The environments

The repository defines three Pixi environments in its pixi.toml.

Commands use the default environment unless you pass another one with -e, as in pixi install -e jazzy.

Build

From the root of your clone:

pixi install

Each Aerostack2 package has a pixi.toml of its own, and Pixi builds every one of them as a package, in the order their dependencies require. The first build downloads ROS 2 and compiles the whole of Aerostack2, so it takes a while. Later builds only redo what changed.

Change the code

Edit any package, then build again:

pixi install

Pixi tracks the files of each package. It rebuilds the packages you changed and the packages that depend on them, so a change to a header in as2_core reaches every node built on it. pixi run and pixi shell check the same way before they start, so you can skip pixi install and let them rebuild.

Every package is installed into the environment as a copy, the way a released package would be. There's no equivalent of colcon's --symlink-install, so a change to a Python file or a launch file needs a rebuild too.

Run your changes

The repository's environment holds Aerostack2 and ros2 pkg, and little else. Check that a package is built with:

pixi run ros2 pkg list | grep as2_

To fly with your changes, run them in a project. The multirotor simulator project has a pixi.toml that installs Aerostack2 as one of its dependencies, together with the ROS 2 tools and the tasks that start the drone. Point that dependency at your clone instead. With the project cloned next to Aerostack2:

[dependencies]
aerostack2 = { path = "../aerostack2/aerostack2" }

Then start the drone from the project as usual:

cd project_as2_multirotor_simulator
pixi run launch

The project builds Aerostack2 from your clone, and rebuilds it whenever you change it, so each pixi run launch flies your latest code. The project has its own build cache, so its first build compiles Aerostack2 again. It builds for the project's distro, which is Jazzy by default in the multirotor simulator project. Use pixi run -e humble launch for Humble.

What doesn't work

The Pixi environments don't include colcon. as2 build and as2 test don't work in them, and neither do the package tests. Run the linters through the git hooks, as in Setting up, and let the pull request's checks run the tests on Linux.

Free up space

Pixi keeps the build of every package under .pixi/bld, and after many rebuilds it can take tens of gigabytes. To remove it:

pixi clean --build

The next pixi install compiles Aerostack2 from scratch again. pixi clean alone also removes the environments.

Next steps