title: Installing lessc with NPM - UNABLE_TO_VERIFY_LEAF_SIGNATURE
body: <p>I want to install the <strong>lessc</strong> provided from <a href="https://npmjs.org" rel="nofollow">NPM</a>. (on OSX)</p>
  
  <p>Firstly, I installed the current version of NodeJs: 0.10.15.<br>
  It includes NPM.</p>
  
  <p>Now I launch the famous command: </p>
  
  <p><code>npm install -g lessc</code></p>
  
  <p>and I obtain this error:</p>
  
  <pre><code>npm install -g lessc
  npm http GET https://registry.npmjs.org/lessc
  npm http GET https://registry.npmjs.org/lessc
  npm http GET https://registry.npmjs.org/lessc
  npm ERR! Error: UNABLE_TO_VERIFY_LEAF_SIGNATURE
  npm ERR!     at SecurePair.&lt;anonymous&gt; (tls.js:1350:32)
  npm ERR!     at SecurePair.EventEmitter.emit (events.js:92:17)
  npm ERR!     at SecurePair.maybeInitFinished (tls.js:963:10)
  npm ERR!     at CleartextStream.read [as _read] (tls.js:463:15)
  npm ERR!     at CleartextStream.Readable.read (_stream_readable.js:320:10)
  npm ERR!     at EncryptedStream.write [as _write] (tls.js:366:25)
  npm ERR!     at doWrite (_stream_writable.js:219:10)
  npm ERR!     at writeOrBuffer (_stream_writable.js:209:5)
  npm ERR!     at EncryptedStream.Writable.write (_stream_writable.js:180:11)
  npm ERR!     at write (_stream_readable.js:573:24)
  </code></pre>
  
  <p>On the net, I found a <a href="http://thomashunter.name/blog/npm-ssl-errors/" rel="nofollow">workaround</a>:</p>
  
  <pre><code>npm config set strict-ssl false
  </code></pre>
  
  <p>But when I relaunch the command, I get now:</p>
  
  <pre><code>npm install -g lessc
  npm http GET https://registry.npmjs.org/lessc
  npm http 404 https://registry.npmjs.org/lessc
  npm ERR! 404 'lessc' is not in the npm registry.
  npm ERR! 404 You should bug the author to publish it
  npm ERR! 404 
  npm ERR! 404 Note that you can also install from a
  npm ERR! 404 tarball, folder, or http url, or git url.
  
  npm ERR! System Darwin 12.4.0
  npm ERR! command "node" "/usr/local/bin/npm" "install" "-g" "lessc"
  npm ERR! cwd /Users/me
  npm ERR! node -v v0.10.15
  npm ERR! npm -v 1.3.5
  npm ERR! code E404
  </code></pre>
  
  <p>I'm very new to NodeJs world and its packager. </p>
  
  <p>Is there something I can do to manage to install <code>lessc</code>?</p>
  
  <p>Maybe I forgot some env variables.</p>