> The strange thing is these tests are passed on our build bots.

RHEL8 has a very strict security policy by default. I'm not sure if any OS run on buildbot has a security policy as strict as RHEL8?

> Maybe bumping used protocol version will help to pass tests on your box.

I tried to tune the SSLContext in many different ways but it doesn't work. The problem comes from the .pem files.

I confirm that copying .pem files from Lib/test/ into Lib/test/test_asyncio/ does fix the issue.

> And by looking at https://github.com/python/cpython/commit/6d8c1abb003a4cb05f1ddcf0eeddeeeed513cd57#diff-a8e7dbb528601706db0f01d01332bb76 it seems that those certs are just copied from test/ within test_asyncio/. So by copying over the old certs, the tests actually pass.

In this case, I don't see the point of having two copies of the same files.

PR 10826 does the right fix: remove .pem files from Lib/test/test_asyncio/ and reuse .pem files from Lib/test/.