title: GAE: raise ValueError('must be "yes" or "no", not %r' % values)
body: <p>A popup on my desktop recently offered to update GoogleAppEngineLauncher, and I agreed to it.</p>
  
  <p>My Python apps in PyCharm then showed "unrecognized reference" for "google" in <code>from google.appengine.api import users</code> or any other reference to "google.appengine.api".</p>
  
  <p>So I launched GoogleAppEngineLauncher and clicked something, and it looked like it did an unzip or something. That made the PyCharm reference errors go away.</p>
  
  <p>When I then tried to launch my app with my old configuration, it had a problem with "Additional options". Apparently it no longer recognizes "-p 8081" or "-c". So I changed them to "--port 8081" and "--clear_datastore". Now it terminates with the following stacktrace:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/dev_appserver.py", line 194, in &lt;module&gt;
      _run_file(__file__, globals())
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/dev_appserver.py", line 190, in _run_file
      execfile(script_path, globals_)
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 545, in &lt;module&gt;
      main()
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 535, in main
      options = PARSER.parse_args()
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1688, in parse_args
      args, argv = self.parse_known_args(args, namespace)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1720, in parse_known_args
      namespace, args = self._parse_known_args(args, namespace)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1926, in _parse_known_args
      start_index = consume_optional(start_index)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1866, in consume_optional
      take_action(action, args, option_string)
    File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1794, in take_action
      action(self, namespace, argument_values, option_string)
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/boolean_action.py", line 67, in __call__
      raise ValueError('must be "yes" or "no", not %r' % values)
  ValueError: must be "yes" or "no", not '.'
  </code></pre>
  
  <p>I tried running "helloworld" in GoogleAppEngineLauncher and got the following in the LogConsole:</p>
  
  <pre><code>*** Running dev_appserver with the following flags:
      --skip_sdk_update_check=yes --port=8081 --admin_port=8000 --clear_datastore
  Python command: /usr/bin/python2.7
  Traceback (most recent call last):
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/dev_appserver.py", line 194, in &lt;module&gt;
      _run_file(__file__, globals())
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/dev_appserver.py", line 190, in _run_file
      execfile(script_path, globals_)
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 545, in &lt;module&gt;
      main()
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 535, in main
      options = PARSER.parse_args()
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1678, in parse_args
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1710, in parse_known_args
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1916, in _parse_known_args
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1856, in consume_optional
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1784, in take_action
    File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/boolean_action.py", line 67, in __call__
      raise ValueError('must be "yes" or "no", not %r' % values)
  ValueError: must be "yes" or "no", not '/Users/lindsay/Projects/PyCharm/Zephyr/gae-tutorial/helloworld'
  </code></pre>
  
  <p>This seems to be more or less the same error as from running my app in PyCharm.</p>
  
  <p>I am under tremendous time pressure on this project, and this is completely blocking me. Any help will be most appreciated.</p>