Linux opencv independent installation : not found in CMake

Question

I am creating an object tracking program which rely on OpenCV. Thus I want to be able to test it with different versions of OpenCV but I have linking errors.

I installed the last version of OpenCV (a69b435c928f422fb5f99c02cf2dcae57dcf820a) in the following folder : /usr/local/opencv/opencv-trunk instead of the usual /usr/local .

Then I followed also the official tutorial to use OpenCV with CMake in Linux, but I had the following "normal" error :

CMake Error at CMakeLists.txt:11 (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:

    OpenCVConfig.cmake
    opencv-config.cmake

  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 installed.


-- Configuring incomplete, errors occurred!

So I did what was suggested and added the following line in my CMakeLists.txt :

# Find independently installed OpenCV libraries
set(OpenCV_DIR "/usr/local/opencv/opencv-trunk/share/OpenCV")

This is the complete CMakeLists.txt file :

# Find independently installed OpenCV libraries
set(OpenCV_DIR "/usr/local/opencv/opencv-trunk/share/OpenCV")

cmake_minimum_required(VERSION 2.8)
project( DisplayImage )
add_executable( DisplayImage DisplayImage.cpp )

find_package( OpenCV REQUIRED )
include_directories( ${OpenCV_INCLUDE_DIRS} )
target_link_libraries( DisplayImage ${OpenCV_LIBS} )

Now I have the following error and I don't find how to deal with it.

CMake Error at CMakeLists.txt:12 (find_package):
  Found package configuration file:

    /usr/local/opencv/opencv-trunk/share/OpenCV/OpenCVConfig.cmake

  but it set OpenCV_FOUND to FALSE so package "OpenCV" is considered to be NOT FOUND.

-- Configuring incomplete, errors occurred!

If you have already faced that issue in such context your solutions are welcomed ;)

Answer 1

If you are running IntelliJ or any other IDE, just try re-building CMake cache (or just remove your build directory and run cmake utility again).

I believe this is not the best practice - to set the configuration variable like OpenCV_DIR hard-coded in the CMakeLists.txt . Try setting it manually, as an environment variable to the cmake utility:

OpenCV_DIR=/usr/local/Cellar/opencv3/3.1.0_2/share/OpenCV/ cmake ..

or set your IDE to make this for you: