Install ROS 2 Jazzy Desktop

Now the operating-system prerequisites and ROS repository should be ready.

The pinned Jazzy guide recommends the Desktop installation when you want ROS, RViz, demos, and tutorials:

sudo apt update
sudo apt install ros-jazzy-desktop

This course uses the Desktop install because later Units rely on beginner demos and graphical tools such as Turtlesim and rqt_graph.

Do not confuse package installation with shell configuration

When apt finishes, ROS packages exist on disk.

That does not mean every terminal automatically knows about them.

Keep these as two separate facts:

INSTALLATION
/opt/ros/jazzy/... exists

SHELL ENVIRONMENT
current terminal has sourced setup files

You will prove the second fact in the next lesson.

Inspect the installation

Try:

ls /opt/ros/jazzy

You should see the installed ROS distribution tree.

You can also ask apt about the package:

apt list --installed 2>/dev/null | grep '^ros-jazzy-desktop/'

The exact package output formatting may vary. The important evidence is that the Jazzy desktop package is installed.

Controlled prediction

Before sourcing anything, open a brand-new terminal and predict what this command will do:

ros2 --help

Depending on shell startup configuration, it may work already or it may report command not found.

Either result can make sense.

The next lesson explains why.

Checkpoint

Record:

Jazzy install directory exists: yes/no
Desktop package installed: yes/no
Did ros2 work in a new terminal before manual sourcing: yes/no
My explanation: