MORIO DNA　（森尾のひとりごと）

Package: darknet_ros GitHub - leggedrobotics/darknet_ros: YOLO ROS: Real-Time Object Detection for ROS Error: [darknet_ros-1] process has died [pid 31789, exit code -11, cmd /home/ecb/catkin_ws/devel/lib/darknet_ros/darknet_ros camera/rgb/image_raw:=camera/rgb/image_raw __name:=darknet_ros __log:=/home/ecb/.ros/log/d366a8d4-e518-11ee-b34d-b38592e7db45/darknet_ros-1.log]. Environment: OS: Ubuntu 20.04 ROS: Noetic Solution: I installed OpenCV of 4.5.1 from source instead of the version 4.5.4. The version of OpenCV was very important for my environment. OpenCV:  4.5.1 worked.  4.5.2 worked. 4.5.4 didn't work.

Solution: 1) Search the error log for the name of the package in question. 2) Open the package folder in catkin_ws/src 3) Edit CMakeLists.txt in the folder as follows: Remove "signals" from the find_package lists. (Before) find_package(Boost REQUIRED COMPONENTS system thread signals ) (After) find_package(Boost REQUIRED COMPONENTS system thread) Alternatively, you may need to look for a package in /usr/lib/x86_64-linux-gnu folder instead of catkin_ws/src folder. Even in that case, edit **** -config.cmake file as above. The cause of the error: The "signals" library is removed in version of 1.69.0 and later of the Boost. In my case, I installed the version of 1.81.0.