attribute macro's `call_site()` hygiene should come from the macro's name, not the `#[]`

I tried this code:

https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=ade138e8d44ac15e91fb351253675a23

my-macros/lib.rs:

use proc_macro2::TokenStream;
use quote::ToTokens;

#[proc_macro_attribute]
pub fn my_attr(
    attr: proc_macro::TokenStream,
    item: proc_macro::TokenStream,
) -> proc_macro::TokenStream {
    match main(attr.into(), item.into()) {
        Ok(retval) => retval.into(),
        Err(err) => err.into_compile_error().into(),
    }
}

fn main(_attr: TokenStream, item: TokenStream) -> syn::Result<TokenStream> {
    let mut item: syn::ItemFn = syn::parse2(item)?;
    item.sig = syn::parse_quote! {
        fn my_test_fn(arg: u8)
    };
    if cfg!(feature = "reset_hygiene") {
        Ok(syn::parse_str(&item.to_token_stream().to_string())?)
    } else {
        Ok(item.to_token_stream())
    }
}

my-code/lib.rs:

macro_rules! m {
    (
        $(#[$meta:meta])*
        $vis:vis fn $($rest:tt)*
    ) => {
        $(#[$meta])*
        $vis fn $($rest)*
    };
}

m! {
    #[my_macros::my_attr]
    pub fn my_test_fn() {
        dbg!(arg);
    }
}

I expected to see this happen: compile without error because the attribute macro adds the arg argument to the function definition and the hygiene used is from my_attr in the invocation of m!

Instead, this happened: got an error:

error[E0425]: cannot find value `arg` in this scope
  --> src/lib.rs:15:14
   |
15 |         dbg!(arg);
   |              ^^^ not found in this scope

Meta

rustc version 1.83.0 on playground

also has same issue on 1.85.0-nightly (2024-12-28 8742e0556dee3c64f714) on playground

Start by running the linked Rust Playground reproduction and compare the two paths in my-macros/lib.rs, including the reset_hygiene branch, with the macro_rules! invocation in my-code/lib.rs. Trace how the attribute macro's generated function parameter and the dbg!(arg) reference receive hygiene information. Done means the reproduction compiles with the hygiene taken from my_attr in the m! invocation.