What needs to be fixed?

In the Rust book under Hygiene section for the following code:

macro_rules! foo {
    ($v:ident) => (let $v = 3);
}

fn main() {
    foo!(x);
    println!("{}", x);
}

There is missing a semi-colon at the line let $v = 3 which doesn't compile in Rust Playground

Page(s) Affected

https://doc.rust-lang.org/1.7.0/book/macros.html#hygiene