title: Error building opencv with cmake on raspberry pi
body: <p>I'm trying to build opencv-3.4.0 (with opencv_contrib-3.4.0) on Raspberry Pi. I'm getting a cmake build error after a 99 % , what should I change?</p>
  
  <p>After I tried "make -j4" in the opencv-3.4.0/build folder, it successfully completed its process until 99%. Before that, configuration and generation part is done with cmake-gui.</p>
  
  <p>Here is the error I am getting on the terminal</p>
  
  <pre><code>    make[2]: *** [modules/python3/CMakeFiles/opencv_python3.dir/build.make:63: modules/python3/CMakeFiles/opencv_python3.dir/__/src2/cv2.cpp.o] Error 1
      make[1]: *** [CMakeFiles/Makefile2:4018: modules/python3/CMakeFiles/opencv_python3.dir/all] Error 2
      make: *** [Makefile:163: all] Error 2
  </code></pre>
  
  <p>What could be the problem?</p>