title: CMake Error buildir" does not appear to contain CMakeLists.txt
body: <p>I tried to run</p>
  
  <pre><code>cmake .
  </code></pre>
  
  <p>but encountered this error:</p>
  
  <pre><code>In-source builds not allowed.  Please make a new directory (called 
  a build
  directory) and run CMake from there.  You may need to remove
  CMakeCache.txt.
  </code></pre>
  
  <p>I did as instructed but got an error stating that:</p>
  
  <pre><code>"buildir" does not appear to contain CMakeLists.txt.
  </code></pre>