进行论文里的一个安装过程，到最后一步：
catkin build ze_vio_ceres
运行结果：
报错：
Errors << ze_ros_msg:cmake /home/zzy/uslam_ws/logs/ze_ros_msg/build.cmake.004.log
CMake Error at /home/zzy/uslam_ws/src/rpg_ultimate_slam_open/common/ze_ros_msg/CMakeLists.txt:4 (find_package):
By not providing "Findcatkin_simple.cmake" in CMAKE_MODULE_PATH this
project has asked CMake to find a package configuration file provided by
"catkin_simple", but CMake did not find one.
Could not find a package configuration file provided by "catkin_simple"
with any of the following names:
catkin_simpleConfig.cmake
catkin_simple-config.cmake
Add the installation prefix of "catkin_simple" to CMAKE_PREFIX_PATH or set
"catkin_simple_DIR" to a directory containing one of the above files. If
"catkin_simple" provides a separate development package or SDK, be sure it
has been installed.
cd /home/zzy/uslam_ws/build/ze_ros_msg; catkin build --get-env ze_ros_msg | catkin env -si /usr/bin/cmake /home/zzy/uslam_ws/src/rpg_ultimate_slam_open/common/ze_ros_msg --no-warn-unused-cli -DCATKIN_DEVEL_PREFIX=/home/zzy/uslam_ws/devel/.private/ze_ros_msg -DCMAKE_INSTALL_PREFIX=/home/zzy/uslam_ws/install -DCMAKE_BUILD_TYPE=Releas; cd -
请问该怎么解决？
这个错误是由于缺少catkin_simple这个包导致的。请确保catkin_simple包已经安装并且在CMAKE_MODULE_PATH路径下。
可以通过在终端输入"sudo apt-get install ros-melodic-catkin-simple"来安装catkin_simple包，或者手动下载安装。
然后再次运行 "catkin build ze_vio_ceres" 命令即可解决问题
望采纳！！！
将catkin_simple下载到你的工作区，https://github.com/catkin/catkin_simple