AppEngine: ningún módulo llamado pyasn1.compat.binary

Sigo recibiendo el siguiente error cuando golpeo mi servidor AppEngine:

ERROR    2017-09-20 07:16:06,978 wsgi.py:263] 
Traceback (most recent call last):
  File "/usr/lib/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/usr/lib/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/usr/lib/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 96, in LoadObject
    __import__(cumulative_path)
  File "/home/dclochri/Projects/react-seed/server/main.py", line 3, in <module>
    from controllers import organization_controller
  File "/home/dclochri/Projects/react-seed/server/controllers/organization_controller.py", line 4, in <module>
    import rest_controller as rest
  File "/home/dclochri/Projects/react-seed/server/controllers/rest_controller.py", line 4, in <module>
    import google.oauth2.id_token
  File "/home/dclochri/Projects/react-seed/lib/google/oauth2/id_token.py", line 22, in <module>
    from google.auth import jwt
  File "/home/dclochri/Projects/react-seed/lib/google/auth/jwt.py", line 53, in <module>
    from google.auth import _service_account_info
  File "/home/dclochri/Projects/react-seed/lib/google/auth/_service_account_info.py", line 22, in <module>
    from google.auth import crypt
  File "/home/dclochri/Projects/react-seed/lib/google/auth/crypt/__init__.py", line 39, in <module>
    from google.auth.crypt import rsa
  File "/home/dclochri/Projects/react-seed/lib/google/auth/crypt/rsa.py", line 17, in <module>
    from google.auth.crypt import _python_rsa
  File "/home/dclochri/Projects/react-seed/lib/google/auth/crypt/_python_rsa.py", line 27, in <module>
    from pyasn1.codec.der import decoder
  File "/home/dclochri/Projects/react-seed/lib/pyasn1/codec/der/decoder.py", line 7, in <module>
    from pyasn1.type import univ
  File "/home/dclochri/Projects/react-seed/lib/pyasn1/type/univ.py", line 11, in <module>
    from pyasn1.compat import octets, integer, binary
  File "/usr/lib/google-cloud-sdk/platform/google_appengine/google/appengine/tools/devappserver2/python/runtime/sandbox.py", line 1132, in load_module
    raise ImportError('No module named %s' % fullname)
ImportError: No module named pyasn1.compat.binary
INFO     2017-09-20 07:16:06,982 module.py:821] default: "OPTIONS /rest/organizations/create HTTP/1.1" 500 -

Milib dir contienepyasn1 (v0.3.5) ypysasn1 tiene uncompat módulo conbinary.py. Parece quepysasn1 se instala como una dependencia por elgoogle-auth módulo (verrequirements.txt abajo). Las dependencias se instalan conpip install -r requirements.txt -t lib, como lo sugiere elMuestra GAE.

Mi código hasta ahora apenas se desvía de los documentos de muestra para usar Firebase con GAEaquí.

Aquí hay algunos fragmentos de lo que estoy usando:

Python: 2.7.12

gcloud versiones:

Google Cloud SDK 171.0.0
alpha 2017.09.11
app-engine-python 1.9.60
beta 2017.09.11
bq 2.0.25
core 2017.09.11
gsutil 4.27

requerimientos.txt

google-auth==1.1.0
requests==2.18.4
requests-toolbelt==0.7.1

rest_controller.py (retazo)

import json
import webapp2
import google.auth.transport.requests
import google.oauth2.id_token
import requests_toolbelt.adapters.appengine

class RestHandler(webapp2.RequestHandler):
    def dispatch(self):
        """Middleware for all the routes."""
        # Verify the user is authenticated for each request.
        if not self.is_authorized() and self.request.method != 'OPTIONS':
            self.response.set_status(401)
            self.response.write('Unauthorized')
        else:
            super(RestHandler, self).dispatch()

    def get_claims(self):
        """
        Verify the Firebase credentials on the server side via the
        bearer's token.
        """
        auth_headers = self.request.headers['Authorization']
        id_token = auth_headers.split(' ').pop()
        return google.oauth2.id_token.verify_firebase_token(
            id_token, HTTP_REQUEST)

    def get_user_id(self):
        claims = self.get_claims()
        return claims['sub']

    def is_authorized(self):
        """
        Determines if the user is authorized.
        NOTE: We don't have a server-side session, so we are operating based on
        the user's client token. We are basically verifying that the client
        Firebase token is valid by checking it via a server-side request.
        """
        if 'Authorization' in self.request.headers:
            if self.get_claims():
                return True

        return False

Estructura de directorios:

/
  lib/
    (deps from requirements.txt here)
  server/
    controllers/
      (controllers here)
    models/
      (models here)
    main.py
  src/
    (client code here - js, css, etc)
  app.yaml
  appengine_config.py

Esto sucede en OSX Yosemite y Ubuntu 16.04. ¿Hay algo que estoy haciendo mal con las importaciones? ¿Hay algún problema con eloauth ¿módulo?