error[E0631]: type mismatch in function arguments
  --> $DIR/issue-60283.rs:14:13
   |
LL | pub fn foo<T, F>(_: T, _: F)
   |        --- required by a bound in this
LL | where T: for<'a> Trait<'a>,
LL |       F: for<'a> FnMut(<T as Trait<'a>>::Item) {}
   |          ------------------------------------- required by this bound in `foo`
...
LL |     foo((), drop)
   |             ^^^^
   |             |
   |             expected signature of `for<'a> fn(<() as Trait<'a>>::Item) -> _`
   |             found signature of `fn(_) -> _`

error[E0271]: type mismatch resolving `for<'a> <fn(_) {std::mem::drop::<_>} as std::ops::FnOnce<(<() as Trait<'a>>::Item,)>>::Output == ()`
  --> $DIR/issue-60283.rs:14:5
   |
LL | pub fn foo<T, F>(_: T, _: F)
   |        --- required by a bound in this
LL | where T: for<'a> Trait<'a>,
LL |       F: for<'a> FnMut(<T as Trait<'a>>::Item) {}
   |                  ----------------------------- required by this bound in `foo`
...
LL |     foo((), drop)
   |     ^^^ expected bound lifetime parameter 'a, found concrete lifetime

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0271, E0631.
For more information about an error, try `rustc --explain E0271`.