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
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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