Sending a GET request with a body fails silently

[natenorberg]

Apparently, whatwg/fetch throws an error if you make a GET request that has a body defined. There's an issue for it (whatwg/fetch#551) but it doesn't seem like they're willing to change it.

Unfortunately, the error is swallowed with a try/catch, so it took me a while to figure out what was going on. The request never showed up in the network tab, but it would throw a timeout error eventually.

It would be nice if the error could be rethrown if it's something that prevents the fetch call from even happening. Otherwise, we should propagate the error back so it's not hidden.