error: non-defining opaque type use in defining scope
  --> $DIR/issue-88595.rs:22:23
   |
LL |     fn a(&'a self) -> Self::B<'a> {}
   |                       ^^^^^^^^^^^
   |
note: lifetime used multiple times
  --> $DIR/issue-88595.rs:18:6
   |
LL | impl<'a> A<'a> for C {
   |      ^^
LL |     type B<'b> = impl Clone;
   |            ^^

error: could not find defining uses
  --> $DIR/issue-88595.rs:19:18
   |
LL |     type B<'b> = impl Clone;
   |                  ^^^^^^^^^^

error: aborting due to 2 previous errors