error[E0277]: `?` couldn't convert the error to `std::alloc::AllocError`
  --> tests/ui/compile-fail/init/no_error_coercion.rs:16:9
   |
16 | /         try_init!(Self {
17 | |             a: Box::new(42),
18 | |             bar <- init!(Bar { b: 42 }),
19 | |         }? AllocError)
   | |______________________^ the trait `From<Infallible>` is not implemented for `std::alloc::AllocError`
   |
   = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
   = help: the trait `FromResidual<Result<Infallible, E>>` is implemented for `Result<T, F>`
   = note: required for `Result<Foo::new::__InitOk, std::alloc::AllocError>` to implement `FromResidual<Result<Infallible, Infallible>>`
   = note: this error originates in the macro `$crate::__init_internal` which comes from the expansion of the macro `try_init` (in Nightly builds, run with -Z macro-backtrace for more info)