You're reading the documentation for a version of ROS 2 that has reached its EOL (end-of-life), and is no longer officially supported. If you want up-to-date information, please have a look at Galactic.

Maintaining a source checkout of ROS 2

If you have installed ROS 2 from source, there may have been changes made to the source code since the time that you checked it out. To keep your source checkout up to date, you will have to periodically update your ros2.repos file, download the latest sources, and rebuild your workspace.

Update your repository list

Each ROS 2 release includes a ros2.repos file that contains the list of repositories and their version for that release.

Release versions

If you wish to update a particular release, you can get its repository list by specifying the codename of the release in the URL of the following step, e.g. dashing:

cd ~/ros2_ws
mv -i ros2.repos ros2.repos.old
wget https://raw.githubusercontent.com/ros2/ros2/dashing-release/ros2.repos

The format of the name of the release comes from the tag associated with the release here.

Release development branches

If you wish to checkout development branches for a particular release, you can get its repository list by specifying the codename of the release in the URL of the following step, e.g. dashing:

cd ~/ros2_ws
mv -i ros2.repos ros2.repos.old
wget https://raw.githubusercontent.com/ros2/ros2/dashing/ros2.repos

Latest development branches

If you wish to checkout the latest development code for the upcoming ROS release, you can get the relevant repository list by running:

cd ~/ros2_ws
mv -i ros2.repos ros2.repos.old
wget https://raw.githubusercontent.com/ros2/ros2/master/ros2.repos

Update your repositories

You will notice that in the ros2.repos file, each repository has a version associated with it that points to a particular commit hash, tag, or branch name. It is possible that these versions refer to new tags/branches that your local copy of the repositories will not recognize as they are out-of-date. Because of this, you should update the repositories that you have already checked out with the following command:

vcs custom --args remote update

Download the new source code

You should now be able to download the sources associated with the new repository list with:

vcs import src < ros2.repos
vcs pull src

Rebuild your workspace

Now that the workspace is up to date with the latest sources, remove your previous install and rebuild your workspace with, for example:

colcon build --symlink-install

Inspect your source checkout

During your development you may have deviated from the original state of your workspace from when you imported the repository list. If you wish to know the versions of the set of repositories in your workspace, you can export the information using the following command:

cd ~/ros2_ws
vcs export src > my_ros2.repos

This my_ros2.repos file can then be shared with others so that they can reproduce the state of the repositories in your workspace.