windowsservercore: urllib SSL errors

I can't get SSL to work in the container, any ideas welcome:

docker run -it python:3.7.1-windowsservercore
>>> import urllib.request; urllib.request.urlopen("https://letsencrypt.org/")
Traceback (most recent call last):
  File "C:\Python\lib\urllib\request.py", line 1317, in do_open
    encode_chunked=req.has_header('Transfer-encoding'))
  File "C:\Python\lib\http\client.py", line 1229, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "C:\Python\lib\http\client.py", line 1275, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "C:\Python\lib\http\client.py", line 1224, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "C:\Python\lib\http\client.py", line 1016, in _send_output
    self.send(msg)
  File "C:\Python\lib\http\client.py", line 956, in send
    self.connect()
  File "C:\Python\lib\http\client.py", line 1392, in connect
    server_hostname=server_hostname)
  File "C:\Python\lib\ssl.py", line 412, in wrap_socket
    session=session
  File "C:\Python\lib\ssl.py", line 853, in _create
    self.do_handshake()
  File "C:\Python\lib\ssl.py", line 1117, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1051)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python\lib\urllib\request.py", line 222, in urlopen
    return opener.open(url, data, timeout)
  File "C:\Python\lib\urllib\request.py", line 525, in open
    response = self._open(req, data)
  File "C:\Python\lib\urllib\request.py", line 543, in _open
    '_open', req)
  File "C:\Python\lib\urllib\request.py", line 503, in _call_chain
    result = func(*args)
  File "C:\Python\lib\urllib\request.py", line 1360, in https_open
    context=self._context, check_hostname=self._check_hostname)
  File "C:\Python\lib\urllib\request.py", line 1319, in do_open
    raise URLError(err)
urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1051)>
>>>

Bắt đầu bằng cách tái hiện lệnh python:3.7.1-windowsservercore đã được ghi lại và yêu cầu urllib của lệnh này tới letsencrypt.org. Điều tra cấu hình tin cậy chứng chỉ của container và xác minh rằng cùng yêu cầu đó thành công mà không gặp lỗi xác minh chứng chỉ đã được báo cáo.