Cannot use catkin build correctly

Oh my God, I wondered whether I destroyed the whole ROS environment or not, what should I do?

Hello @a13e5c2ddf294571 ,

There are a couple of errors here from what I can see in your image.

First, you are trying to compile from the ~/catkin_ws/src folder, which is not correct. When compiling you have to ALWAYS be in the ~/catkin_ws folder, as explained in the notebook. NEVER compile from the src folder.

Therefore, the build and devel folders that you are trying to remove will also be inside ~/catkin_ws. In your image, you are removing them from ~/catkin_ws/src.

I forgot ''rm -rf build/ devel/ " and “source devel/setup.bash”, thank a lot!