$ rustc badscope.rs
error[E0425]: cannot find value `y` in this scope
 --> badscope.rs:9:24
  |
9 |     println!("y = {}", y);
  |                        ^ help: a local variable with a similar name exists: `x`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0425`.