How to install +nightly?

Question

I don't want to use anything but the stable toolchain for my normal work but would like to be able to debug my macros using cargo expand. I don't even now how to use anything but the default stable toolchain.

Answer 1

You can install nightly rust with rustup toolchain install nightly, then you can run cargo as nightly with rustup run nightly cargo [...more arguments here] or cargo +nightly [...more arguments here]. If you want your normal cargo command to be replaced with nightly as well then you can run rustup default nightly.