ROS 2 Lyrical lab 02 ยท 35 min
Create the robotics workspace
Build a clean colcon overlay at ~/robot_ws and understand each generated directory.
Practice this lab in your browser: Prove the overlay winsUnderstand before building
How this part of ROS 2 works
A colcon workspace separates source files from generated build, install, and log data. Only src is authored by you.
The installed ROS distribution is the underlay; your workspace is an overlay. Sourcing the overlay makes your newly built packages discoverable.
Before you start
- ROS 2 Lyrical sourced
- colcon installed
Files you will touch
~/robot_ws/src/~/robot_ws/build/~/robot_ws/install/~/robot_ws/log/
Step 1
Set up
source /opt/ros/lyrical/setup.bash
mkdir -p ~/robot_ws/src
cd ~/robot_ws
colcon build --symlink-installStep 2
Create the file
# Source the overlay after every successful build.
source ~/robot_ws/install/setup.bash
printenv AMENT_PREFIX_PATHWhat each part does
- 1.mkdir creates the conventional source directory without failing if it exists.
- 2.colcon builds discovered packages and creates setup files; sourcing install/setup.bash activates the overlay.
Step 3
Build, run and inspect
cd ~/robot_ws
colcon list
colcon build --symlink-install
source install/setup.bashProof that it works
- The build finishes without failed packages
- install/setup.bash exists
- The workspace path appears before /opt/ros/lyrical in AMENT_PREFIX_PATH
Recovery notes
- Remove build, install and log only when a clean rebuild is necessary; never remove src.
- Build one package with --packages-select PACKAGE_NAME to isolate errors.