title: Does Django try to translate template variables?
body: <p>I have the following code in my template:</p>
  
  <pre><code>{% blocktrans %}Hello, {{ user.username }}!{% endblocktrans %}
  </code></pre>
  
  <p>This appears on my site as:</p>
  
  <blockquote>
    <p>Hello, !</p>
  </blockquote>
  
  <p>I am sure that the variable is populated (because it shows up correctly if I remove the <code>blocktrans</code> tag), so my question is: does Django attempt to translate variables too? A working code for me was:</p>
  
  <pre><code>{% blocktrans with username=user.username %}Hello, {{ username }}!{% endblocktrans %}
  </code></pre>
  
  <p>However, in the Django core, in one of the templates, there's this code:</p>
  
  <pre><code>{% blocktrans %}You're receiving this email because you requested a password reset for your user account at {{ site_name }}.{% endblocktrans %}
  </code></pre>
  
  <p>So I think this should work, right? Is there an obvious mistake I'm not noticing?</p>