At the "Getting Started Contributing To Rust" meetup there were a number of people who were looking for a way to easily get started developing on rust. After searching for a vagrant file and not finding a prebaked solution somewhere on the internet, I wrote a Vagrantfile for rust development inspired by the Rails-Dev-Box.
If you're just interested in using the rust compiler and aren't interested in modifying rust, then the "rustup" script works.
curl -s https://static.rust-lang.org/rustup.sh | sudo sh
You can find the code here. As always, it's a work in progress and providers apart from VirtualBox are not yet supported.