title: Call to subprocess only works with PyCharm debugger
body: <p>I have made a Python script in which one line makes a call to <code>grep</code> through <code>subprocess</code>:</p>
  
  <pre><code>master_start_time = subprocess.check_output(["grep", "-a", '"Time"', master_wav]).strip()[-23:]
  </code></pre>
  
  <p>When I run it using my Python interpreter (v. 2.7.12), the following error consistently appears, both when executing from PyCharm and through a remote shell (as the script and data reside on a remote machine running Ubuntu 16.04.1): </p>
  
  <pre><code>subprocess.CalledProcessError: Command '['grep', '-a', '"Time"', './DATA/PREDICTING/1014/1014_L.wav']' returned non-zero exit status 1
  </code></pre>
  
  <p>Once I run the script through a remote PyCharm debugger, however, everything runs smoothly. </p>
  
  <p>The following lines appear first in the PyCharm console when debugging. They should summarize the debug configuration.</p>
  
  <pre><code>ssh://{user}@{server}:{port}{path to interpreter} -u {path to PyCharm debugger} --multiproc --qt-support --client '0.0.0.0' --port 35567 --file {path to script}
  pydev debugger: process 18838 is connecting
  </code></pre>
  
  <p>Does anyone know how I can prevent this from appearing?</p>