Operating System: Ubuntu Linux 18.04 Linux 5.0.0-27-generic x86_64
When resolving host to address, and failed to find host, the errno returned is different when using thread-dns or dnspython, and when using ares.
thread-dns returns EAI_NONAME, which makes sense.
dnspython return None, which is a little weird.
ares returns EINTR, which is very weird.
Different resolvers are different? 🤷♂ I'd review PRs that added this fact to the documentation or which got them to behave more like each other in a tested way. There are existing tests for that in test__socket_dns.py, and some are skipped if we're not using the system DNS resolver, perhaps that's a starting point.