error: implementation of `Bar` is not general enough
  --> $DIR/where-for-self-2.rs:21:5
   |
LL |     foo(&X); //~ ERROR implementation of `Bar` is not general enough
   |     ^^^
   |
   = note: Due to a where-clause on `foo`,
   = note: `&'0 _` must implement `Bar` for any lifetime `'0`
   = note: but `&'1 u32` only implements `Bar` for the lifetime `'1`

error: aborting due to previous error