title: What is preventing find_library(c c) from setting the variable c in cmake?
body: <p>In a bare CmakeLists.txt file, I place the following:</p>
  
  <pre><code>find_library (c c)
  find_library (a c)
  </code></pre>
  
  <p>to match the syntax <code>find_library(&lt;var&gt; &lt;lib&gt;)</code></p>
  
  <p>I run <code>cmake .</code>
  I open CMakeCache.txt and find a has been set with the path to libc, and c has not been set at all.</p>
  
  <p>if I instead use <code>set (c "text" CACHE STRING "")</code> c will be set to "text"</p>
  
  <p>Why can I set c with set() but not with find_library()?</p>