FileNotFoundError: [Errno 2] No such file or directory: ‘xacro‘

记录一个小错误：运行 ros2 launch learning_urdf display.launch.py时出现的error:

FileNotFoundError: [Errno 2] No such file or directory: 'xacro'

原因是缺少xacro的依赖，安装一下即可：

 sudo apt install ros-foxy-xacro