I had my standalone installation of OpenCV on my Linux machine and it was running OK. I installed ROS (comes with its OpenCV) and today I cannot run my CMakeLists.txt in any of my OpenCV projects, getting the error of :
CMake Error at CMakeLists.txt:20 (find_package):
By not providing "FindOpenCV.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "OpenCV", but
CMake did not find one.
Could not find a package configuration file provided by "OpenCV" with any
of the following names:
Add the installation prefix of "OpenCV" to CMAKE_PREFIX_PATH or set
"OpenCV_DIR" to a directory containing one of the above files. If "OpenCV"
provides a separate development package or SDK, be sure it has been
Reinstalling OpenCV solved the problem for me, since it re-modified the Environment variable.