title: How can I change the default CMAKE_INSTALL_PREFIX in cmake?
body: <p>I'm using the line:</p>
  
  <pre><code>set(CMAKE_INSTALL_PREFIX "${CMAKE_SOURCE_DIR}/INSTALL" CACHE PATH "Directory for sbnw installation")
  </code></pre>
  
  <p>as described in the <a href="https://cmake.org/cmake/help/v3.0/command/set.html" rel="nofollow noreferrer">docs</a> to change the default install directory from <code>C:/Program Files (x86)/SBNW</code> to <code>project_root/INSTALL</code>. However, I still want users to still be able to choose the default install path. After using this command, the value of <code>CMAKE_INSTALL_PREFIX</code> is still <code>C:/Program Files (x86)/SBNW</code>. Does anybody know why? </p>