Python 3.7's TLS SNI missing
The beta 3.7 does not implement the TLS Server Name Indication (SNI) added in Python 3.7 as SSLContext.sni_callback. This causes unexpected errors in applications that rely on its presence when 3.7 is reported; one example of this is the test suite of the aiocoap package.
The link to the function should provides all necessary information already; please let me know if you want this report more detailed.
Observed using the Docker image pypy:3.7 that reports: Python version: 3.7.9 (7e6e2bb30ac5, Nov 18 2020, 10:55:52) [PyPy 7.3.3-beta0 with GCC 7.3.1 20180303 (Red Hat 7.3.1-5)]