title: Why does NPM 7.17 not install my peer dependencies
body: <p>I have a <code>main</code> project which depends on a package <code>package1</code> in the local file store. <code>package1</code> peer depends on express:</p>
  <pre><code>{
    &quot;name&quot;: &quot;package1&quot;,
    &quot;version&quot;: &quot;1.0.0&quot;,
    &quot;description&quot;: &quot;&quot;,
    &quot;main&quot;: &quot;index.js&quot;,
    &quot;scripts&quot;: {
      &quot;test&quot;: &quot;echo \&quot;Error: no test specified\&quot; &amp;&amp; exit 1&quot;
    },
    &quot;author&quot;: &quot;&quot;,
    &quot;license&quot;: &quot;ISC&quot;,
    &quot;peerDependencies&quot;: {
      &quot;express&quot;: &quot;^4.17.1&quot;
    }
  }
  </code></pre>
  <p>In the folder of the main project I do</p>
  <pre><code>npm install ../packages/package1
  </code></pre>
  <p>With npm@6.x it installs package1 as a link in node_modules of the main project, as expected. It also gives me a warning, that a peer dependency is missing - as expected.</p>
  <p>Now I use npm@7.17 for the same task. Either with <code>--legacy-peer-deps</code> option or without. It installs package1 as a link in node_modules of the main project. But it does NOT install the peer dependency in the main package NOR does it give my a warning, that a peer dependency is missing.</p>
  <p>I exepected either a warning (at least with <code>-legacy-peer_deps</code> switched on) or <code>express</code> installed in the main project. BTW, it also does not get installed in the node_modules of package1.</p>
  <p>Any idea anybody? I'd appreciate it much.</p>