title: No route matches on dynamic page
body: <p>I'm trying to create a dynamic page based on the trial_id from the Trial controller. I have it showing the right url, but get a No route matches [GET] error. I'm using rails 4.2.0 and this worked previously on 3.2, but i think I'm missing something.</p>
  
  <p><strong>View</strong></p>
  
  <pre><code>&lt;% @regions.each do |region, list| %&gt;
    &lt;%= region %&gt;
      &lt;% list.sort{ |a,b| a.site.site_name &lt;=&gt; b.site.site_name }.each do |list| %&gt;
        &lt;% paths = trials_show_path(trial_id: list.trial_id)
           path = paths.gsub("?trial_id=", "/")
        %&gt;
  
  &lt;%= link_to list.site.site_name, path %&gt;
  
  &lt;% end %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p><strong>Show Controller</strong></p>
  
  <pre><code>@results = Trial.trial_id(params[:trial_id])
  </code></pre>
  
  <p><strong>Trial Model</strong></p>
  
  <pre><code>scope :trial_id, -&gt; (trial_id) { where(trial_id: trial_id) }
  </code></pre>
  
  <p><strong>Routes</strong></p>
  
  <pre><code>  get 'trials', :to =&gt; 'trials#index'
    get 'trials/show'
  </code></pre>