BUGFIX: isinstance check is wrong

[keflavich]

This error:

E       TypeError: isinstance() arg 2 must be a type, a tuple of types, or a union

arises if turning internet off and then creating a new socket.

I haven't figured out how to MWE this; it was happening in astroquery.gaia, but the source of the connection is buried behind so many abstraction layers that I'm just lost. I've tried hard. I would possibly recommend not merging this until/unless we have a MWE.

[pllim]

if isinstance(args[0], socket.socket)

It is saying socket.socket is neither a type, a tuple of types, nor a union. Then what is it in your case?

[keflavich]

it was a very weird thing. It claimed to be a socket class, but wasn't registering as such with isinstance. I... I am not sure now. I really need an MWE to test this. Within the gaia-related failures, it looked like it might have been a monkeypatch instance or something like that.... but that seems not to be the case; turn_off_internet doesn't replace socket.socket, it just patches its methods.

tl;dr: I'm confused.

[bsipocz]

we're also ignoring a bunch of socket warnings in the astroquery test suite, those may mess up your debug when done via pytest. Given this is a not sure problem and solution yet I switch this PR to be a draft, so we won't accidentally merge it, until at least there is a clear MWE snippet.

[keflavich]

Thanks @bsipocz, I forgot I could do that. Yes, this should be draft for now.