title: Python error No such file or directory
body: <p>I get the following error: No such file or directory but I'm unsure why. I know it looks easy to explain but I'm unsure what directory its referring to here</p>
  
  <pre><code>env = os.environ.copy()
  env['MY_LIB_PATH'] = '/Users/user/Documents/workspace/projecttest/lib'
  subprocess.call(["test_program",image_url],env=env)
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "test.py", line 20, in &lt;module&gt;
      model = get_model(image.get_image_content())
    File "/Users/user/Documents/workspace/projecttest/utilities.py", line 51, in get)model
      env=env
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 522, in call
      return Popen(*popenargs, **kwargs).wait()
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 709, in __init__
      errread, errwrite)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1326, in _execute_child
      raise child_exception
  OSError: [Errno 2] No such file or directory
  </code></pre>