Working with Public Repositories#

Several parts of the Kangaroo software stack are open source and hosted as public repositories on GitHub. Instead of cloning each one manually, PAL Robotics uses vcstool together with a .repos file to fetch a consistent set of repositories with a single command — the same approach used by the ROS 2 source build itself.

Prerequisites#

vcstool is already included in the PAL Docker image. If you are working outside the container, install it with:

sudo apt-get install python3-vcstool

The `.repos` File#

A .repos file is a YAML file that lists a set of git repositories, their URL and the branch or tag to check out. Create a workspace src folder and add a file, for example kangaroo.repos, with the following content:

repositories:
  launch_pal:
    type: git
    url: https://github.com/pal-robotics/launch_pal.git
    version: master

  pal_urdf_utils:
    type: git
    url: https://github.com/pal-robotics/pal_urdf_utils.git
    version: humble-devel

  pal_sea_arm:
    type: git
    url: https://github.com/pal-robotics/pal_sea_arm.git
    version: humble-devel

  kangaroo_moveit_config:
    type: git
    url: https://github.com/pal-robotics/kangaroo_moveit_config.git
    version: humble-devel

  play_motion2:
    type: git
    url: https://github.com/pal-robotics/play_motion2.git
    version: humble-devel

  urdf_test:
    type: git
    url: https://github.com/pal-robotics/urdf_test.git
    version: humble-devel

  kangaroo_simulation:
    type: git
    url: https://github.com/pal-robotics/kangaroo_simulation.git
    version: humble-devel

Each entry maps a package name to the git repository that provides it and the branch to check out. humble-devel tracks the development branch for ROS 2 Humble, while launch_pal is versioned independently and tracks master.

Importing the Repositories#

From the src folder of your workspace, run vcs import and pass it the .repos file:

mkdir -p ~/exchange/kangaroo_ws/src
cd ~/exchange/kangaroo_ws/src
vcs import < kangaroo.repos

vcs import clones any repository that is not yet present and leaves existing clones untouched. Each repository is checked out at the branch declared in the version field.

Keeping the Workspace Up to Date#

To pull the latest changes for every repository declared in the .repos file, run vcs pull from the same src folder:

vcs pull

You can also check the status of all repositories at once — useful for spotting local modifications before pulling:

vcs status

Building the Workspace#

Once the repositories are imported, install any missing dependencies with rosdep and build the workspace with colcon, from the workspace root:

cd ~/exchange/kangaroo_ws
rosdep install --from-paths src --ignore-src -r -y
colcon build --symlink-install

See Deploying Software to the Robot for how to install the resulting packages onto the robot.

Working with Public Repositories

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