Pass HttpBasicAuth object to requests, rather than a list, which it didn't understand

common/lib/capa/capa/xqueue_interface.py

@@ -60,10 +60,10 @@ class XQueueInterface:
     Interface to the external grading system
     '''
 
-    def __init__(self, url, django_auth, basic_auth=None):
+    def __init__(self, url, django_auth, requests_auth=None):
         self.url  = url
         self.auth = django_auth
-        self.session = requests.session(auth=basic_auth)
+        self.session = requests.session(auth=requests_auth)
         
     def send_to_queue(self, header, body, file_to_upload=None):
         '''

lms/djangoapps/courseware/module_render.py

@@ -19,14 +19,20 @@ from xmodule_modifiers import replace_static_urls, add_histogram, wrap_xmodule
 
 from courseware.courses import (has_staff_access_to_course,
                                 has_staff_access_to_location)
+from requests import HttpBasicAuth
 
 log = logging.getLogger("mitx.courseware")
 
 
+if settings.XQUEUE_INTERFACE['basic_auth'] is not None:
+    requests_auth = HttpBasicAuth(*settings.XQUEUE_INTERFACE['basic_auth'])
+else:
+    requests_auth = None
+
 xqueue_interface = XQueueInterface(
     settings.XQUEUE_INTERFACE['url'],
     settings.XQUEUE_INTERFACE['django_auth'],
-    settings.XQUEUE_INTERFACE['basic_auth'],
+    requests_auth,
 )