ROS运行launch文件时出错

错误如下：

No such file or directory: /home/dwy/catkin_ws/src/turtlebot3/turtlebot3_description/urdf/turtlebot3_.urdf.xacro None None
while processing /home/dwy/catkin_ws/src/turtlebot3/turtlebot3_bringup/launch/includes/description.launch.xml:
Invalid <param> tag: Cannot load command parameter [robot_description]: command [/opt/ros/kinetic/lib/xacro/xacro --inorder '/home/dwy/catkin_ws/src/turtlebot3/turtlebot3_description/urdf/turtlebot3_.urdf.xacro'] returned with code [2]. 

Param xml is <param command="$(arg urdf_file)" name="robot_description"/>
The traceback for the exception was written to the log file

分析：

很明显是没有运行环境

解决：

在终端运行下面的命令：

source ~/.bashrc