reqwest: Hangs in OSX reading certain sized responses unless specifying `Connection::close`

I’m making an authenticated GET request that succeeds, but any attempt to read_to_string or read_to_end just hangs indefinitely, but only under all the following criteria:

• OSX (works fine on linux)
• responses in the range of 3835-16120 bytes (~260 bytes short of the 4K/16K boundaries).
• over SSL (works fine if I make the same request through a local http nginx proxy)

This is the debug output of an example Response object I see before it hangs during reading:

Response { inner: Response { status: Ok, headers: Headers { Date: Wed, 23 Nov 2016 03:06:35 GMT, X-Frame-Options: DENY, Strict-Transport-Security: max-age=0; includeSubDomains; preload, X-Data-Type: directory, Connection: keep-alive, Content-Length: 7452, Content-Type: application/json; charset=utf-8, }, version: Http11, url: "https://api.algorithmia.com/v1/connector/data/anowell/foo", status_raw: RawStatus(200, "OK"), message: Http11Message { is_proxied: false, method: None, stream: Wrapper { obj: Some(Reading(SizedReader(remaining=7452))) } } } }

And yet, I haven’t managed to repro this with a simple test script to just reqwest::get some public URL in that size range, so I’m still missing some contributing factor. I’ve also tried an old build of my client which used hyper+openssl, and it had no issue.

Things on my mind to try still:

• Read in smaller chunks to see if perhaps read_to_end is waiting on the wrong number of bytes
• Put together the minimal repro using an API key for a shareable test account
• Try a bit harder to find a repro outside of our API