*+TOOLCHAIN*::
If Cargo has been installed with rustup, and the first argument to `cargo`
begins with `+`, it will be interpreted as a rustup toolchain name (such
as `+stable` or `+nightly`).
See the link:https://github.com/rust-lang/rustup/[rustup documentation]
for more information about how toolchain overrides work.
*-h*::
*--help*::
Prints help information.
*-Z* _FLAG_...::
Unstable (nightly-only) flags to Cargo. Run `cargo -Z help` for
details.