kolibri: 500 Internal Server error on import channel

Summary

While trying to import CK12 channel in a fresh development repo:

System information

• Version: develop branch
• Operating system: OSX
• Browser: Chrome

Traceback or relevant snippet from server.log or browser console

[02/Oct/2017 01:56:39] "GET /api/tasks/?1506902199429=1506902199429 HTTP/1.1" 200 2
ERROR    Internal Server Error: /api/tasks/startremoteimport/
Traceback (most recent call last):
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/django/core/handlers/base.py", line 149, in get_response
    response = self.process_exception_by_middleware(e, request)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/django/core/handlers/base.py", line 147, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/django/views/decorators/csrf.py", line 58, in wrapped_view
    return view_func(*args, **kwargs)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/rest_framework/viewsets.py", line 87, in view
    return self.dispatch(request, *args, **kwargs)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/rest_framework/views.py", line 466, in dispatch
    response = self.handle_exception(exc)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/rest_framework/views.py", line 463, in dispatch
    response = handler(request, *args, **kwargs)
  File "kolibri/tasks/api.py", line 102, in startremoteimport
    get_content_database_file_url(channel_id)).status_code
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/requests/api.py", line 97, in head
    return request('head', url, **kwargs)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/requests/api.py", line 57, in request
    return session.request(method=method, url=url, **kwargs)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/requests/sessions.py", line 475, in request
    resp = self.send(prep, **send_kwargs)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/requests/sessions.py", line 585, in send
    r = adapter.send(request, **kwargs)
  File "/Users/mac/.venvs/kolibri/lib/python2.7/site-packages/requests/adapters.py", line 477, in send
    raise SSLError(e, request=request)
SSLError: [SSL: SSLV3_ALERT_HANDSHAKE_FAILURE] sslv3 alert handshake failure (_ssl.c:661)
[02/Oct/2017 01:56:40] "POST /api/tasks/startremoteimport/?1506902199198=1506902199198 HTTP/1.1" 500 109686

After setting “http” instead of “https” here, as suggested by @jamalex, no more 500 error, but transfer still fails, with no apparent errors in console/terminal:

[02/Oct/2017 02:43:15] "GET /api/tasks/?1506904995392=1506904995392 HTTP/1.1" 200 151
INFO     Downloading data for channel id 95a52b386f2c485cb97dd60901674a98
INFO:kolibri.content.management.commands.importchannel:Downloading data for channel id 95a52b386f2c485cb97dd60901674a98
DEBUG    URL to fetch: http://studio.learningequality.org/content/databases/95a52b386f2c485cb97dd60901674a98.sqlite3
DEBUG:kolibri.content.management.commands.importchannel:URL to fetch: http://studio.learningequality.org/content/databases/95a52b386f2c485cb97dd60901674a98.sqlite3
DEBUG    Destination: /Users/mac/.kolibri/content/databases/95a52b386f2c485cb97dd60901674a98.sqlite3
DEBUG:kolibri.content.management.commands.importchannel:Destination: /Users/mac/.kolibri/content/databases/95a52b386f2c485cb97dd60901674a98.sqlite3
[02/Oct/2017 02:43:16] "GET /api/tasks/?1506904996392=1506904996392 HTTP/1.1" 200 957
[02/Oct/2017 02:43:17] "GET /api/tasks/?1506904997392=1506904997392 HTTP/1.1" 200 957

Will try installing packages suggested at SO next, to see if it solves something…