warning: not reporting region error due to nll
  --> $DIR/regions-trait-object-subtyping.rs:25:5
   |
LL |     x //~ ERROR lifetime bound not satisfied
   |     ^

warning: not reporting region error due to nll
  --> $DIR/regions-trait-object-subtyping.rs:32:5
   |
LL |     x //~ ERROR mismatched types
   |     ^

error: unsatisfied lifetime constraints
  --> $DIR/regions-trait-object-subtyping.rs:23:51
   |
LL |   fn foo3<'a,'b>(x: &'a mut Dummy) -> &'b mut Dummy {
   |  _________--_--_____________________________________^
   | |         |  |
   | |         |  lifetime `'b` defined here
   | |         lifetime `'a` defined here
LL | |     // Without knowing 'a:'b, we can't coerce
LL | |     x //~ ERROR lifetime bound not satisfied
LL | |      //~^ ERROR cannot infer an appropriate lifetime
LL | | }
   | |_^ return requires that `'a` must outlive `'b`

error: unsatisfied lifetime constraints
  --> $DIR/regions-trait-object-subtyping.rs:32:5
   |
LL | fn foo4<'a:'b,'b>(x: Wrapper<&'a mut Dummy>) -> Wrapper<&'b mut Dummy> {
   |         --    -- lifetime `'b` defined here
   |         |
   |         lifetime `'a` defined here
LL |     // We can't coerce because it is packed in `Wrapper`
LL |     x //~ ERROR mismatched types
   |     ^ return requires that `'b` must outlive `'a`

error: aborting due to 2 previous errors