error[E0499]: cannot borrow `x` as mutable more than once at a time --> $DIR/issue-65131.rs:14:22 | LL | get_pair(&mut x, &mut x); | -------- ------ ^^^^^^ second mutable borrow occurs here | | | | | first mutable borrow occurs here | first borrow later used by call error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0499`.