RobotnixAcademy

Unit 07 · lesson

Build, Source, Run, and Inspect

Now close the loop.

Diagram tracing Python node source and package metadata through colcon, the install space, ros2 run, and the live publisher/subscriber topic.
Diagram tracing Python node source and package metadata through colcon, the install space, ros2 run, and the live publisher/subscriber topic.

Diagrams open at a readable shape-aware scale. Zoom or expand when you need more detail.

Build only your package

From the workspace root:

cd ~/ros2_ws
source /opt/ros/jazzy/setup.bash
colcon build --packages-select robotnix_pubsub --symlink-install

Read the summary. Do not source a failed build.

Use a clean terminal

source /opt/ros/jazzy/setup.bash
source ~/ros2_ws/install/local_setup.bash

Check executable discovery:

ros2 pkg executables robotnix_pubsub

Run the talker

ros2 run robotnix_pubsub talker

Run the listener

In another sourced terminal:

ros2 run robotnix_pubsub listener

You should see publishing and receiving log messages.

Inspect your own graph

In a third terminal:

ros2 node list
ros2 topic list -t
ros2 topic info /student_chatter --verbose
ros2 interface show std_msgs/msg/String

Now every command from Units 3–4 works on a system you authored.

Checkpoint

Build an evidence trace:

Python source
→ package metadata/entry point
→ colcon install
→ ros2 run
→ nodes
→ /student_chatter
→ String messages