title: Unable to build and install Valgrind on macOS High Sierra
body: <p>I cannot install Valgrind on macOS High Sierra. It's not available through <code>brew</code>. I've tried with <a href="https://github.com/msgpack/msgpack-c/issues/525" rel="noreferrer">3.10</a>. After <code>make install</code>, I get this message:</p>
  
  <pre><code>configure: error: Valgrind works on Darwin 10.x, 11.x, 12.x, 13.x and 14.x (Mac OS X 10.6/7/8/9/10)
  </code></pre>
  
  <p>Homebrew says:</p>
  
  <pre><code>valgrind: This formula either does not compile or function as expected on macOS
  versions newer than Sierra due to an upstream incompatibility.
  Error: An unsatisfied requirement failed this build.
  </code></pre>