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.

Pre-release Testing

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 /etc/apt/sources.list.d/ros2-latest.list and change ros2 with 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
```
Update the apt index:
```
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 /etc/apt/sources.list.d/ros2-latest.list:
```
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
```