Running Simulations

All simulations are launched through the sim CLI. It builds the workspace, sets up the environment, and runs the ROS 2 launch file for the specified robot.

Basic usage

Inside devcontainer

sim docker <robot_name>

For example, to run the arm simulation:

Inside devcontainer

sim docker arm

Options

Option	Description
--no-build	Skip the colcon build step. Use this when you haven’t changed any code and want a faster startup.
--build-only	Build the workspace but don’t launch the simulation. Useful for checking if your changes compile.

Inside devcontainer

# Skip building (already built)
sim docker arm --no-build

# Only build, don't launch
sim docker arm --build-only

Cleaning the workspace

To remove build artifacts and do a clean rebuild:

Inside devcontainer

sim clean

This deletes build/, install/, and log/ directories. Use this when you encounter unexplained build failures.

Troubleshooting

Build fails with cryptic errors: Run sim clean to delete stale build artifacts, then try again. Stale artifacts are the most common cause of unexplained build failures.

Gazebo window doesn’t appear: The display starts automatically with the Dev Container. Connect via your VNC viewer at localhost:5900 and verify it works with xeyes. If you restarted the container manually and the display isn’t running, restart it with .devcontainer/x_server.sh.

Package not found errors after launch: Try running sim clean and building again.