title: subprocess.CalledProcessError: what *is* the error?
body: <pre><code>import subprocess
  
  cmd = "grep -r * | grep jquery"
  print cmd
  
  subprocess.check_output(cmd, shell=True)
  </code></pre>
  
  <p><strong>subprocess.CalledProcessError: Command 'grep -r * | grep jquery' returned non-zero exit status 1</strong></p>
  
  <p>I can execute that command in my shell without issues. How can I see the <strong>actual</strong> error in python?</p>
  
  <p><em>The snippet is part of a larger script which takes multiple arguments and chains the grep commands + adds some excludes (I don't need to grep log files or minified JavaScript. Hence the pedantic syntax.</em></p>
  
  <p><em>Python 2.7.10</em></p>