実際のところ
$ ros2 run xacro xacro src/robot_description/urdf/robot_arm.urdf.xacro > /tmp/check.urdf
$ check_urdf /tmp/check.urdf
robot name is: robot
---------- Successfully Parsed XML ---------------
root Link: world has 1 child(ren)
child(1): base_link
child(1): left_arm_base_link
child(1): left_arm_link1
child(1): left_arm_link2
child(1): left_arm_link3
child(1): left_arm_link4
child(1): left_arm_link5
child(1): left_arm_link6
child(1): left_arm_link7
