http://python-requests.org/ is showing:

It's the same case for subdomains, including docs.python-requests.org, which is breaking the building of sphinx documentation which refer to requests docs: see https://github.com/brunns/mbtest/runs/6549875114?check_suite_focus=true#step:9:31 for an example.