title: Pug mixins from external file not working
body: <p>I am working with Pug and I wanted to create some mixins to make some reusable components across whole project. I wanted to create some files just to make mixins separated and categorised. The problem occurs when I want to include file with mixins into my main file. For example:</p>
  
  <pre><code>body
      block content
          include ./components/mixins/_mixins.pug
          +user_avatar('', '#', 'Daniel')
  </code></pre>
  
  <p>This does not work (when I want to include mixins from separate file). I got this error: <code>jade_mixins.user_avatar is not a function</code></p>
  
  <p>But when I include mixin in the file it works: </p>
  
  <pre><code>body
      block content
          mixin user_avatar(avatar_url, profile_url, name)
              .user(class='4u 6u(small) 12u(xsmall)')
                  a(href=profile_url)
                      .user-avatar-thumbnail.is-active(style="background-image: url('" + avatar_url + "')")
                      if name
                          span.user-name=name
          +user_avatar('', '#', 'Daniel')
  </code></pre>
  
  <p>Any clue what to do to fix it? And yeah, the path is correct. To compile pug I use the <code>laravel-elixir-jade</code> package for laravel's elixir.</p>