Confusing error message when using #[pyclass] with a struct called Probe

[Tiwalun]

Bug Description

The following code fails to compile, with a somewhat confusing error message:

use pyo3::prelude::*;

#[pyclass]
struct Probe {}

The error message is:

error[E0782]: expected a type, found a trait
 --> src/lib.rs:4:8
  |
4 | struct Probe {}
  |        ^^^^^
  |
help: you can add the `dyn` keyword if you want a trait object
  |
4 | struct dyn Probe {}
  |        +++

For more information about this error, try `rustc --explain E0782`.
error: could not compile `pyo3-repro` (lib) due to 1 previous error

rust-analyzer suggests that this might be due to the trait Probe here:

pyo3/src/impl_/pyclass/probes.rs

Line 16 in 926f5cf

pub trait Probe {

I'm not sure if this can be fixed, but it would be nice to at least have a clearer error message to indicate that the struct can't be called Probe.

Steps to Reproduce

Compile the code mentioned above.

Backtrace

No response

Your operating system and version

Ubuntu 24.04

Your Python version (python --version)

Python 3.12.3

Your Rust version (rustc --version)

rustc 1.83.0 (90b35a623 2024-11-26)

Your PyO3 version

0.23.3

How did you install python? Did you use a virtualenv?

apt

Additional Info

This was observed when updating PyO3 from version 0.21 to 0.22, so it seems to have changed in version 0.22.

[Icxolu]

Thanks for reporting, should be fixed by #4794.