RUSTC_VERSION != CARGO_VERSION

Author: Jon Gjengset

src/doc/src/reference/environment-variables.md

@@ -357,7 +357,7 @@ let out_dir = env::var("OUT_DIR").unwrap();
 * `CARGO_PKG_<var>` - The package information variables, with the same names and values as are [provided during crate building][variables set for crates].
 * `RUSTC_VERSION` - The version of rustc used by the cargo that invokes
 		    the build script. Its constituent parts are also
-		    available as `CARGO_VERSION_MAJOR`, `_MINOR`, and
+		    available as `RUSTC_VERSION_MAJOR`, `_MINOR`, and
 		    `_PATCH`.
 
 [unix-like platforms]: ../../reference/conditional-compilation.html#unix-and-windows