issue-38147-1.diff

--- issue-38147-1.stderr	2018-05-30 14:47:45.876944584 +0200
+++ issue-38147-1.nll.stderr	2018-06-04 12:18:36.039563618 +0200
@@ -1,11 +1,13 @@
-error[E0389]: cannot borrow data mutably in a `&` reference
+error[E0596]: cannot borrow immutable item `*self.s` as mutable
   --> $DIR/issue-38147-1.rs:27:9
    |
 LL |     fn f(&self) {
-   |          ----- use `&mut self` here to make mutable
+   |          ----- help: consider changing this to be a mutable reference: `&mut self`
 LL |         self.s.push('x'); //~ ERROR cannot borrow data mutably
-   |         ^^^^^^ assignment into an immutable reference
+   |         ^^^^^^ cannot borrow as mutable
+   |
+   = note: the value which is causing this path not to be mutable is...: `*self`
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0389`.
+For more information about this error, try `rustc --explain E0596`.