About Error :cannot launch node of type

[ghost]

I am asking this question from Japan. Your blog is very informative. I have one question.
When I write "roslaunch carto_mapper mapper.launch", I get the following error.

【Error Description】
ERROR: cannot launch node of type [cartographer_ros/cartographer_node]: cartographer_ros ROS path [0]=/opt/ros/noetic/share/ros ROS path [1]=/home/user/ydlidar_ros_ws/src ROS path [2]=/home/user/catkin_ws/src ROS path [3]=/opt/ros/noetic/share ERROR: cannot launch node of type [cartographer_ros/cartographer_occupancy_grid_node]: cartographer_ros ROS path [0]=/opt/ros/noetic/share/ros ROS path [1]=/home/user/ydlidar_ros_ws/src ROS path [2]=/home/user/catkin_ws/src ROS path [3]=/opt/ros/noetic/share

If you know the cause, I would like to know.

[msadowski]

The error tells you that cartographer_ros cannot be found. Looking at the ROS wiki and the package index Cartographer hasn't been released for Noetic. This means that you either need to build the package yourself (might be nontrivial) or look for some alternatives (either changing the system to 18.04 and going with ROS Melodic or finding a docker container with Cartographer running).

Good luck!