Could not find a package configuration file provided by “gflags_catkin“ 的参考解决方法

写在前面

自己的测试环境：
Ubuntu20.04
ROS-Noetic

一、问题描述

CMake Error at /***/devel/share/catkin_simple/cmake/catkin_simple-extras.cmake:38 (find_package):
  By not providing "Findgflags_catkin.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "gflags_catkin", but CMake did not find one.

  Could not find a package configuration file provided by "gflags_catkin"
  with any of the following names:

    gflags_catkinConfig.cmake
    gflags_catkin-config.cmake

  Add the installation prefix of "gflags_catkin" to CMAKE_PREFIX_PATH or set
  "gflags_catkin_DIR" to a directory containing one of the above files.  If
  "gflags_catkin" provides a separate development package or SDK, be sure it
  has been installed.

二、解决方法

出现这个问题的原因主要是缺少 gflags_catkin 包，但是使用 sudo apt-get install ros-noetic-gflags-catkin 并不能找到 gflags_catkin 包，因此需要下载源码，然后再使用。

首先从 https://github.com/ethz-asl/gflags_catkin 下载 gflags_catkin 包，并把 gflags_catkin 包 与自己的 package 放在同一位置。然后再次编译即可。

参考链接

[1] ethz-asl. gflags_catkin. https://github.com/ethz-asl/gflags_catkin, 2019-02-25/2024-07-28. (commit ID: fc38fc5)