`type-repetition-in-bounds` gives an unhelpful suggestion when lifetimes are involved

[Kriskras99]

Summary

The suggestion for type-repetition-in-bounds is unclear if the duplication is because of a lifetime.

Reproducer

I tried this code:

struct Struct<'a, K: 'a>
where K: Clone {
    phantom: std::marker::PhantomData<&'a K>,
}

I expected to see this happen:

help: consider combining the bounds: `K: 'a + Clone`

(or no warning at all)
Instead, this happened:

help: consider combining the bounds: `K: Clone`

Version

rustc: 1.88.0-nightly (d6a325d93 2025-05-03)
binary: rustc
commit-hash: d6a325d93a84077580c677f89affbe45682606c3
commit-date: 2025-05-03
host: x86_64-unknown-linux-gnu
release: 1.88.0-nightly
LLVM version: 20.1.4

Additional Labels

No response

[samueltardieu]

@rustbot claim
@rustbot label +L-nursery

[samueltardieu]

The message will be changed to the (hopefully) clearer, and more correct (including lifetimes):

error: type `K` has already been used as a bound predicate
  --> tests/ui/type_repetition_in_bounds.rs:148:5
   |
LL |     K: Clone,
   |     ^^^^^^^^
   |
   = help: consider combining the bounds: `K: 'a + Clone`