error: service constructor must take `&self`, not `&mut self`: a `&mut self` factory can leak an exclusive borrow of program state across an `.await`
  --> tests/ui/gprogram_fails_mut_service_ctor.rs:13:5
   |
13 | /     pub fn service(&mut self) -> MyService {
14 | |         MyService
15 | |     }
   | |_____^
