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 Humble.
Many ROS packages are provided as pre-built binaries. Usually, you will get the released version of binaries when following Installation. There are also pre-released versions of binaries that are useful for testing before making an official release. This article describes several options if you would like to try out pre-released versions of ROS binaries.
Debian testing repository
For Debian-based operating systems, you can install binary packages from the ros-testing repository.
Make sure you have a working ROS 2 installation from Debian packages (see Installation).
Edit (with sudo) the file
ros2-testing. For example, on Ubuntu Focal the contents should look like the following:
# deb http://packages.ros.org/ros2/ubuntu focal main deb http://packages.ros.org/ros2-testing/ubuntu focal main
sudo apt update
You can now install individual packages from the testing repository, for example:
sudo apt install ros-dashing-my-just-released-package
Alternatively, you can move your entire ROS 2 installation to the testing repository:
sudo apt dist-upgrade
Once you are finished testing, you can switch back to the normal repository by changing back the contents of
deb http://packages.ros.org/ros2/ubuntu focal main # deb http://packages.ros.org/ros2-testing/ubuntu focal main
and doing an update and upgrade:
sudo apt update sudo apt dist-upgrade