title: opencv cmake warning meanings: CMakeLists.txt:1066 (include)
body: <p>I am now building from source the <code>opencv4.1.0</code> with <code>cmake3.13</code>. The cmake configuration gives a warning message saying:</p>
  
  <pre><code>CMake Warning at cmake/OpenCVGenSetupVars.cmake:54 (message):
    CONFIGURATION IS NOT SUPPORTED: validate setupvars script in install
    directory
  Call Stack (most recent call first):
    CMakeLists.txt:1066 (include)
  </code></pre>
  
  <p>What does this warning mean? Does that need be carefully addressed for starting the building process?</p>