anchor.diff:  In some cases you can also check these variables by examining the cache using
   ccmake or cmake-gui.
   
  -[[building-the-example]]
  -Building the Example
  -~~~~~~~~~~~~~~~~~~~~
  +# Building the Example
   
   [source,bash]
   ----
  
positive.code: endif()
  ----
  
  [[exported_variables]]
  Exported Variables
  ^^^^^^^^^^^^^^^^^^
  
  After a package is found it will often export variables which can inform the user
  where to find the library, header, or executable files. Similar to the `XXX_FOUND`
  
negative.code: = Including Third Party Library
  :toc:
  :toc-placement!:
  
  toc::[]
  
  # Introduction
  
  Nearly all non-trivial projects will have a requirement for including third party
  libraries, headers, or programs. CMake has support for finding the path to these tools using
  