cmake.out

CMake Warning (dev) at /usr/share/cmake-3.16/Modules/FindOpenGL.cmake:275 (message):
  Policy CMP0072 is not set: FindOpenGL prefers GLVND by default when
  available.  Run "cmake --help-policy CMP0072" for policy details.  Use the
  cmake_policy command to set the policy and suppress this warning.

  FindOpenGL found both a legacy GL library:

    OPENGL_gl_LIBRARY: /usr/lib/x86_64-linux-gnu/libGL.so

  and GLVND libraries for OpenGL and GLX:

    OPENGL_opengl_LIBRARY: /usr/lib/x86_64-linux-gnu/libOpenGL.so
    OPENGL_glx_LIBRARY: /usr/lib/x86_64-linux-gnu/libGLX.so

  OpenGL_GL_PREFERENCE has not been set to "GLVND" or "LEGACY", so for
  compatibility with CMake 3.10 and below the legacy GL library will be used.
Call Stack (most recent call first):
  modules/highgui/cmake/detect_gtk.cmake:40 (find_package)
  modules/highgui/cmake/init.cmake:35 (include)
  modules/highgui/cmake/init.cmake:39 (add_backend)
  cmake/OpenCVModule.cmake:298 (include)
  cmake/OpenCVModule.cmake:361 (_add_modules_1)
  cmake/OpenCVModule.cmake:385 (ocv_glob_modules)
  CMakeLists.txt:927 (ocv_register_modules)
This warning is for project developers.  Use -Wno-dev to suppress it.