bash: /home/hsl/catkin_ws/devel/setup.bash: 没有那个文件或目录
但是文件里面是有这个source /opt/ros/noetic/setup.bash source ~/catkin_ws/devel/setup.bash的且不重复，而且运行roslaunch mbot_description display_mbot_base_urdf.launch总是显示RLException: [display_mbot_base_urdf.launch] is neither a launch file in package [mbot_description] nor is [mbot_description] a launch file name
The traceback for the exception was written to the log file，该怎么解决。所有的办法都试过了就是出错误
你这就是没有配置工作空间的环境变量，找不到相应的包。方法是依次输入以下两条语句
echo "source /home/hsl/catkin_ws/devel/setup.bash" >> ~/.bashrc
source ~/.bashrc
还有source /opt/ros/noetic/setup.bash source ~/catkin_ws/devel/setup.bash。这是你ros的环境变量。要跟工作空间的环境变量分辨清楚