Unexpected follow-up errors after proc-macro attribute panic

I tried this code:

// auxiliary/panic-inducing.rs
extern crate proc_macro;

use proc_macro::TokenStream;

#[proc_macro_attribute]
pub fn panic_inducing(_: TokenStream, _: TokenStream) -> TokenStream {
    panic!();
}

// attr-panic-macro.rs
#![feature(custom_inner_attributes)]
#![panic_inducing::panic_inducing]

#[macro_use]
extern crate panic_inducing;

fn main() {}

I expected to see this happen: the compilation fails only with custom attribute panicked.

Instead, this happened:

error: custom attribute panicked
  --> <path>/attr-macro-panic.rs:6:1
   |
LL | #![panic_inducing::panic_inducing]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: explicit panic

error: `#[panic_handler]` function required, but not found

error: unwinding panics are not supported without std
   |
   = help: using nightly cargo, use -Zbuild-std with panic="abort" to avoid unwinding
   = note: since the core library is usually precompiled with panic="unwind", rebuilding your crate with panic="abort" may not be enough to fix the problem

error[E0601]: `main` function not found in crate `attr_macro_panic`

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0601`.

Meta

rustc --version --verbose:

rustc 1.92.0 (ded5c06cf 2025-12-08)
binary: rustc
commit-hash: ded5c06cf21d2b93bffd5d884aa6e96934ee4234
commit-date: 2025-12-08
host: x86_64-unknown-linux-gnu
release: 1.92.0
LLVM version: 21.1.3

This error was discovered when running ./x ~.rs --bless in the UI test for #99478.

The reproduction uses auxiliary/panic-inducing.rs and attr-panic-macro.rs; first run the UI test for #99478 with ./x ~.rs --bless and inspect its expected diagnostics. Trace why the panic produces the follow-up errors, and consider the issue done when the test reports only the custom-attribute panic.