Can't test with cookies since localhost is a public suffix
Since localhost is detected as a public suffix, we drop the cookies set for it. As a result, it is almost impossible to write tests for cookies.
The best I can do is
--save-cookies, but I'd also like to test that they were indeed sent in the next request
I vaguely remember having an issue with using 127.0.0.1 directly. Something about some machines not using it? Maybe we can use 0.0.0.0, the loopback address instead?