@1357029556 在 cmake报错 中说：
CMake Warning at /opt/ros/melodic/share/catkin/cmake/catkin_package.cmake:166 (message):
catkin_package() DEPENDS on 'gazebo' but neither 'gazebo_INCLUDE_DIRS' nor
'gazebo_LIBRARIES' is defined.
应该是没有安装好gazebo相关的开发库造成的
sudo apt-get install gazebo9 libgazebo9-dev重新装下试试