diagnostic refers to the wrong object's lifetime

Code

use std::{any::Any, cell::RefCell, rc::Rc};

fn doit(it: &dyn Any) {
    if let Some(s) = it.downcast_ref::<&str>() {
        println!("{s}");
    }
}
fn main() {
    // this works fine:
    let s = Rc::new(RefCell::new("hello, inner!"));
    let inner: &str = &s.borrow();
    doit(&inner as &dyn Any);
    // the commented line at the bottom doesn't compile:
    // `s` dropped here while still borrowed
    //
    // but it seems the real issue is not the lifetime of `s` but the
    // intermediate `Ref` created by `borrow()` that gets dropped too early.
    //
    //doit(&s.borrow() as &dyn Any);
}

Current output

error[E0597]: `s` does not live long enough
(...)
`s` dropped here while still borrowed

Desired output

casting Ref<'_, &'static str> to &dyn Any requires that `s` is borrowed for 'static

Rationale and extra context

the lifetime of s isn't the problem - it's the implicit temporary Ref object that does not live long enough

Other cases

No response

Rust Version

rustc 1.79.0 (129f3b996 2024-06-10)
binary: rustc
commit-hash: 129f3b9964af4d4a709d1383930ade12dfe7c081
commit-date: 2024-06-10
host: aarch64-apple-darwin
release: 1.79.0
LLVM version: 18.1.7

Anything else?

thanks to @Dirbaio for both figuring out the actual problem and suggesting the improved diagnostic!

Start by compiling the provided Rust reproducer with rustc 1.79.0 and compare the current E0597 diagnostic with the desired message. Trace the compiler diagnostic path for the cast involving Ref<'_, &'static str> and the implicit temporary created by borrow(). Done means the diagnostic identifies the temporary Ref object's lifetime rather than incorrectly referring to s.