Comment 5 for bug 1661199

Think about that: Your proxy returns 403 and you have 20 repositories, and now get 20 messages, each 100 lines long because your proxy decided to go fancy.

And of course: If reported as an actual error message, these things also become python exceptions.

Or did you really just mean the message after the status code (RFC calls it reason-phrase) and not the entire response body? That's usually reasonable short. That said, apt-cacher-ng gets very creative with these messages, other proxies stick to the standard messages. And the HTTP standard says a client should ignore the messages completely, as they are legacy (compare RFC 7230, 3.1.2).

So I'm not sure it's worthwhile to display the reason-phrase either: It's only used by apt-cacher-ng and the standard says we should ignore its contents.