Could not find a package configuration file provided by “GeographicLib“解决

ubuntu20.04 system
compilation error :

By not providing "FindGeographicLib.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "GeographicLib", but CMake did not find one.

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

    GeographicLibConfig.cmake
    geographiclib-config.cmake

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

Solved :

1 installation

sudo apt-get install ros-melodic-geographic-*
sudo apt-get install geographiclib-*
sudo apt-get install libgeographic-*

2 Establish a soft link
In the ubuntu20.04 environment, after installing the package, the cmake compilation still cannot find the path.
This is because:

The geographiclib-dev installer puts the FindGeographicLib.cmake file in: /usr/share/cmake/geographiclib/FindGeographicLib.cmake

The correct location is: /usr/share/cmake-3.16/Modules   

Indeed it depends by the version of cmake currently installed. 

solve:

sudo ln -s /usr/share/cmake/geographiclib/FindGeographicLib.cmake /usr/share/cmake-3.16/Modules/

Compile again, successfully.