Rust Stable is great, but not all of the macro (the Macro 2.0 stuff) support is on the stable release channel yet. There are still some things you can't do on s

Rust Stable is great, but not all of the macro (the Macro 2.0 stuff) support is on the stable release channel yet. There are still some things you can't do on stable (or can do, but inconveniently). (Rocket also depends on a few other nightly only features. Things will likely change in the future once the Macro stuff stabilizes though) There is also the matter of compiler plugins... which may never land in stable.