https://github.com/LarryDong/FusionTracking安装gflags之后catkin build失败，报错信息：

    1. By not providing "Findgflags_catkin.cmake" in CMAKE_MODULE_PATH this
    2. project has asked CMake to find a package configuration file provided by
    3. "gflags_catkin", but CMake did not find one.
    5. Could not find a package configuration file provided by "gflags_catkin"
    6. with any of the following names:
    8. gflags_catkinConfig.cmake
    9. gflags_catkin-config.cmake

    可能原因：　确实gflags_catkin相关的依赖。
    尝试了sudo apt-get 安装gflags以及源编译安装的方式，都没有解决。
    尚未解决？？？

    下载了gflags_catkin之后，再使用sudo catkin build之后解决？？？ 但是这样在clion下cmake失败，存在权限问题。删除所有编译生成的文件之后，重新catkin build，又成功了？？？