title: Find the dependency that brought another dependency in Node.js
body: <p>Now that <a href="http://blog.npmjs.org/post/110924823920/npm-weekly-5" rel="nofollow">npm installs dependencies in a flat structure</a> the <code>node_modules</code> dir is crowded with lots and lots of dependencies and I have a hard time tracing why a particular dependency is there.</p>
  
  <p>For example, when installing one of my dependencies, I get a warning that <a href="https://github.com/IndigoUnited/node-cross-spawn-async" rel="nofollow">cross-spawn-asyc</a> is deprecated and <a href="https://github.com/IndigoUnited/node-cross-spawn" rel="nofollow">cross-spawn</a> should be used instead. But having a closer look I see that my dependency is actually using <em>cross-spawn</em> but apparently something deeper in its dependency hierarchy still uses the old <em>cross-spawn-async</em> library.</p>
  
  <p>How can I find that dependency which causes this problem rather than going through <code>package.json</code> of 100+ directories under <code>node_modules</code>?</p>