title: Plone app crashes immediately on launch - how to get useful error output?
body: <p>I installed Plone, added some packages to my <code>buildout.cfg</code>, and ran <code>bin/buildout</code> successfully. However, now, when I run <code>bin/instance restart</code>, it crashes immediately with no error output:</p>
  
  <pre><code>$ bin/instance restart
  . 
  daemon process restarted, pid=29508
  $ ps aux | grep 29508
  ubuntu   29626  0.0  0.0  12944   928 pts/0    S+   11:52   0:00 grep --color=auto 29508
  $ ps aux | grep plone
  ubuntu   29743  0.0  0.0  12944   984 pts/0    S+   11:53   0:00 grep --color=auto plone
  </code></pre>
  
  <p>There's also nothing in <code>var/log/instance.log</code> besides an entry indicating that the server <em>started</em>:</p>
  
  <pre><code>------
  2018-02-08T11:53:24 INFO ZServer HTTP server started at Thu Feb  8 11:53:24 2018
      Hostname: 0.0.0.0
      Port: 8080
  </code></pre>
  
  <p>How can I find out what caused the crash?</p>