Robot Description Issues

The controller manager launch expands a xacro file into the robot description before it starts anything else. If that expansion fails the launch aborts before any controller loads, and the error comes from xacro rather than from Isaac ROS Deploy.

The Launch Aborts With a xacro or URDF Error

Symptom

The launch exits during startup and no controller is loaded. The error text names xacro or a URDF parsing problem, and is easy to lose among the rest of the launch output.

Solution

Reproduce the expansion by hand to see the error on its own. Inspect the controller manager launch file to identify the xacro file and arguments selected for the active hardware type, then run the equivalent command:

xacro /path/to/robot_description.urdf.xacro \
    argument_name:=argument_value

A successful run prints the expanded URDF to standard output. Run this check against each hardware-specific ros2_control xacro. This is the first of the validation steps in How to bring your own embodiment. Passing it is what lets you attribute a later failure to the controller configuration rather than to the description.