解决办法;
cd ~/catkin_ws
rm -rf build/ devel/
catkin_make
source devel/setup.bash
sudo apt-get install ros-noetic-roslaunch
输入roscore后
解决办法;
cd ~/catkin_ws
rm -rf build/ devel/
catkin_make
source devel/setup.bash
sudo apt-get install ros-noetic-roslaunch
输入roscore后