title: Creating an user without a password
body: <p>I'm trying to create user without password like this:</p>
  
  <pre><code>sudo adduser \
     --system \
     --shell /bin/bash \
     --gecos ‘User for managing of git version control’ \
     --group \
     --disabled-password \
     --home /home/git \
     git
  </code></pre>
  
  <p>It's created fine. But when I try to login under the git user I'm getting the password entering:</p>
  
  <pre><code>su git
  Password:...
  </code></pre>
  
  <p>When I leave it empty I get an error:</p>
  
  <pre><code>su: Authentication failed
  </code></pre>
  
  <p>What's wrong?  </p>