title: CMake finds Boost but the imported targets not available for Boost version
body: <p>I use CMake to find Boost. Boost is found, but CMake errors out with</p>
  
  <blockquote>
    <p>Imported targets not available for Boost version</p>
  </blockquote>
  
  <p>See the complete error (from macOS) below. What am I doing wrong?</p>
  
  <pre><code>CMake Warning at /Applications/CMake.app/Contents/share/cmake-3.6/Modules/FindBoost.cmake:743 (message):
    Imported targets not available for Boost version 106300
  Call Stack (most recent call first):
    /Applications/CMake.app/Contents/share/cmake-3.6/Modules/FindBoost.cmake:842 (_Boost_COMPONENT_DEPENDENCIES)
  /Applications/CMake.app/Contents/share/cmake-3.6/Modules/FindBoost.cmake:1395 (_Boost_MISSING_DEPENDENCIES)
  CMakeLists.txt:6 (find_package)
  
  Boost version: 1.63.0
  Found the following Boost libraries:
    thread
  CMake Warning at /Applications/CMake.app/Contents/share/cmake-3.6/Modules/FindBoost.cmake:743 (message):
    Imported targets not available for Boost version 106300
  Call Stack (most recent call first):
    /Applications/CMake.app/Contents/share/cmake-3.6/Modules/FindBoost.cmake:842 (_Boost_COMPONENT_DEPENDENCIES)
    /Applications/CMake.app/Contents/share/cmake-3.6/Modules/FindBoost.cmake:1395 (_Boost_MISSING_DEPENDENCIES)
    CMakeLists.txt:7 (find_package)
  </code></pre>