問題：

CMake Error at CMakeLists.txt:4 (find_package):
By not providing “Findcatkin.cmake” in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by “catkin”, but
CMake did not find one.

Could not find a package configuration file provided by “catkin” with any
of the following names:

catkinConfig.cmake
catkin-config.cmake

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

解決辦法

在CMakeLists.txt中加入
find_package( PkgConfig )
pkg_check_modules( EIGEN3 REQUIRED eigen3 )