error[E0038]: the trait `B` cannot be made into an object
  --> $DIR/issue-98500.rs:11:14
   |
LL | struct S(Box<dyn B>);
   |              ^^^^^ `B` cannot be made into an object
   |
note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
  --> $DIR/auxiliary/not-object-safe.rs:4:8
   |
LL |     fn f();
   |        ^ ...because associated function `f` has no `self` parameter
LL |     fn f2(self: &Arc<Self>);
   |        ^^ ...because method `f2`'s `self` parameter cannot be dispatched on
   |
  ::: $DIR/issue-98500.rs:5:11
   |
LL | pub trait B where
   |           - this trait cannot be made into an object...
   = help: consider moving `f` to another trait
   = help: consider moving `f2` to another trait

error: aborting due to previous error

For more information about this error, try `rustc --explain E0038`.