title: Why does npm list -g lead to npm ERR! missing error?
body: <p>npm returns the following message after using <code>npm list -g</code></p>
  
  <blockquote>
  <pre><code>npm ERR! missing: atom-package-manager@*, required by undefined@undefined
  npm ERR! missing: opal-npm-wrapper@git://github.com/anthonny/opal-npm-wrapper.git#0.1.1, required by asciidoctor.js@1.5.2
  npm ERR! missing: xmlhttprequest@~1.6.0, required by asciidoctor.js@1.5.2
  </code></pre>
  </blockquote>
  
  <p>screenshot: </p>
  
  <p><img src="https://img.itc.cn/photo/jRlgBxSrmgv" alt=""></p>