title: Upstart task generated by foreman doesn't find file?
body: <p>I used foreman to export my Procfile to an upstart task.</p>
  
  <p>Procfile:</p>
  
  <pre><code>web: bundle exec rails server
  websocket: bundle exec rails runner websocket-server/em_websocket.rb
  </code></pre>
  
  <p>One of the upstart tasks (they are very alike and fail with the same error):</p>
  
  <pre><code>start on starting app-web
  stop on stopping app-web
  respawn
  
  env PORT=5000
  
  setuid app
  
  chdir /var/www/app
  
  exec bundle exec rails server
  </code></pre>
  
  <p>And the error (I got it via dmesg):</p>
  
  <pre><code>[35207.676836] init: Failed to spawn app-websocket-1 main process: unable to execute: No such file or directory
  [35207.679577] init: Failed to spawn app-web-1 main process: unable to execute: No such file or directory
  </code></pre>
  
  <p>When I switch to the app user, I am actually able to run <code>bundle exec rails server</code> from the given directory.</p>
  
  <p>Is there any way to pin down the error a little more? I didn't find any related logs in <code>/var/log/upstart/</code>.</p>