error[E0502]: cannot borrow `x` as immutable because it is also borrowed as mutable
  --> $DIR/borrowck-report-with-custom-diagnostic.rs:8:13
   |
LL |     let y = &mut x;
   |             ------ mutable borrow occurs here
LL |
LL |     let z = &x;
   |             ^^ immutable borrow occurs here
...
LL |     y.use_mut();
   |     ----------- mutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
  --> $DIR/borrowck-report-with-custom-diagnostic.rs:21:21
   |
LL |             let y = &x;
   |                     -- immutable borrow occurs here
LL |
LL |             let z = &mut x;
   |                     ^^^^^^ mutable borrow occurs here
...
LL |             y.use_ref();
   |             ----------- immutable borrow later used here

error[E0499]: cannot borrow `x` as mutable more than once at a time
  --> $DIR/borrowck-report-with-custom-diagnostic.rs:36:17
   |
LL |         let y = &mut x;
   |                 ------ first mutable borrow occurs here
LL |
LL |         let z = &mut x;
   |                 ^^^^^^ second mutable borrow occurs here
...
LL |         y.use_mut();
   |         ----------- first borrow later used here

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0499, E0502.
For more information about an error, try `rustc --explain E0499`.