Is there a Cargo build on Homebrew?

Doesn't seem so - looks like we'll have to install cargo separately if we use homebrew, which is kind of unfortunate. Guess I'll just go back to using the rustup until brew installs cargo as well as rust.

I went ahead and added this to homebrew cask! Here's my PR[0]. Hopefully it will be merged soon.

[0]: https://github.com/caskroom/homebrew-cask/pull/6591

I looked into adding one to homebrew-cask[0], but it isn't quite as easy as the rust nightly, because it doesn't use a pkg. It shouldn't be too hard though, to do it from that tar.

[0]: https://github.com/caskroom/homebrew-cask

Unsure, it's been a long time since I've actually owned a Mac. It doesn't look like it, though.