warning: trait item `hello` from `B` shadows identically named item from supertrait
  --> $DIR/common-ancestor.rs:17:5
   |
LL |     fn hello(&self) {
   |     ^^^^^^^^^^^^^^^
   |
note: item from `A` is shadowed by a subtrait item
  --> $DIR/common-ancestor.rs:10:5
   |
LL |     fn hello(&self) {
   |     ^^^^^^^^^^^^^^^
note: the lint level is defined here
  --> $DIR/common-ancestor.rs:6:9
   |
LL | #![warn(supertrait_item_shadowing_definition)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: trait item `hello` from `B` shadows identically named item from supertrait
  --> $DIR/common-ancestor.rs:25:8
   |
LL |     ().hello();
   |        ^^^^^
   |
note: item from `B` shadows a supertrait item
  --> $DIR/common-ancestor.rs:17:5
   |
LL |     fn hello(&self) {
   |     ^^^^^^^^^^^^^^^
note: item from `A` is shadowed by a subtrait item
  --> $DIR/common-ancestor.rs:10:5
   |
LL |     fn hello(&self) {
   |     ^^^^^^^^^^^^^^^
note: the lint level is defined here
  --> $DIR/common-ancestor.rs:5:9
   |
LL | #![warn(supertrait_item_shadowing_usage)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: 2 warnings emitted