npm update broke npm : <p>I just followed <a href="https://stackoverflow.com/questions/6237295/how-can-i-update-node-js-and-npm-to-the-next-versions">this guide</a> to update npm (as my nodered camera module wasn't working) and ran</p>

<pre><code>npm install -g npm
</code></pre>

<p>but now my npm install seems completely broken. If I just type </p>

<pre><code>npm
</code></pre>

<p>or </p>

<pre><code>npm update
</code></pre>

<p>I get </p>

<blockquote>
  <p>/usr/local/lib/node_modules/npm/bin/npm-cli.js:79
        let notifier = require('update-notifier')({pkg})
        ^^^</p>
  
  <p>SyntaxError: Block-scoped declarations (let, const, function, class)
  not yet supported outside strict mode</p>
</blockquote>

<p>I've tried </p>

<pre><code>sudo apt-get remove npm
sudo apt-get install npm
</code></pre>

<p>but the reinstall didn't help.</p>

<p>I think my node version needs upgrading from v4.8.2 but I thought that was only possible with npm?</p>
