title: Intermittent "OSError: [Errno 7] Argument list too long" with short command (~125 chars)
body: <p>This code running under apache2+mod_wsgi on Linux sometimes produces the following output.</p>
  
  <pre><code>   notes.py
              cmd_list = [
                      'abc_generate_pdf',
                      '--cdb-url-prefix', model.config('cdb_url_prefix'),
                      '--request-cid', request_cid,
              ]
              log.info("About to run: {!r}".format(cmd_list))
              subprocess.Popen(cmd_list)
  ...
  2014-07-16 11:03:44,779 INFO     pid:17925,140353357215488 abc.webapp.check.notes:198:approval_revoke About to run: ['abc_generate_pdf', '--cdb-url-prefix', 'xxxxdev', '--request-cid', u'xxxxx_xxx_2014-07-15_16.12.50.108807_685932a62c7c6226987acdeda367dbc3']
  2014-07-16 11:03:45,250 ERROR    pid:17925,140353357215488 abc.webapp.check.notes:208:approval_revoke Unknown error; approval not updated.
  Traceback (most recent call last):
    File "/home/abc/abc/webapp/check/notes.py", line 199, in approval_revoke
      subprocess.Popen(cmd_list)
    File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
      errread, errwrite)
    File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child
      raise child_exception
  OSError: [Errno 7] Argument list too long
  </code></pre>
  
  <p>The output has been anonymized slightly, but the character counts remain exact.</p>
  
  <p>The problem seems to happen after the web server has been running for a long time, and goes away with a restart, however it's difficult to pin down exactly what the trigger might be.</p>
  
  <p>Why am I getting an error, and what can I do to prevent it?</p>
  
  <p>This question is very similar to <a href="https://stackoverflow.com/questions/8970121/python-oserror-no-7-argument-list-too-long-in-linux">Python OSError no 7 (Argument list too long ) in linux</a> , which doesn't have a satisfactory answer.</p>
  
  <p>Edit: I should note that the problem also happens under the pure-python werkzeug server.</p>