Comment 0 for bug 1903890

I've just upgraded to Ubuntu 20.10 which comes with python3-openssl version 19.0.1-2. It breaks (at least some) Python applications that use the `requests` library to access HTTPS URLS. For instance, this stack trace (note that I have clipped the first few frames from the stack as they are proprietary):

  File "/home/tkcook/.local/lib/python3.8/site-packages/requests/api.py", line 76, in get
    return request('get', url, params=params, **kwargs)
  File "/home/tkcook/.local/lib/python3.8/site-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)
  File "/home/tkcook/.local/lib/python3.8/site-packages/requests/sessions.py", line 530, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/tkcook/.local/lib/python3.8/site-packages/requests/sessions.py", line 643, in send
    r = adapter.send(request, **kwargs)
  File "/home/tkcook/.local/lib/python3.8/site-packages/requests/adapters.py", line 439, in send
    resp = conn.urlopen(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 670, in urlopen
    httplib_response = self._make_request(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 381, in _make_request
    self._validate_conn(conn)
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 978, in _validate_conn
    conn.connect()
  File "/usr/lib/python3/dist-packages/urllib3/connection.py", line 342, in connect
    self.ssl_context = create_urllib3_context(
  File "/usr/lib/python3/dist-packages/urllib3/util/ssl_.py", line 289, in create_urllib3_context
    context.verify_mode = cert_reqs
  File "/usr/lib/python3/dist-packages/urllib3/contrib/pyopenssl.py", line 438, in verify_mode
    self._ctx.set_verify(_stdlib_to_openssl_verify[value], _verify_callback)
  File "/usr/lib/python3/dist-packages/OpenSSL/SSL.py", line 1119, in set_verify
    self._verify_helper = _VerifyHelper(callback)
  File "/usr/lib/python3/dist-packages/OpenSSL/SSL.py", line 337, in __init__
    self.callback = _ffi.callback(
SystemError: ffi_prep_closure(): bad user_data (it seems that the version of the libffi library seen at runtime is different from the 'ffi.h' file seen at compile-time)