String monkeypatches confuse Faraday.

[pat]

Faraday can accept either strings or URI objects as a url for HTTP connections... and it determines which is which by checking whether the given url responds to host. Unfortunately, your monkeypatch adding the host instance method to String causes Faraday to raise an error if it's given a string url.

Perhaps it's worth reconsidering whether monkeypatching String so heavily is a wise idea - the more this is done, the greater potential for issues like this one.