error[E0277]: the trait bound `Result<(), MyError>: IntoPyCallbackOutput<_>` is not satisfied --> tests/ui/invalid_result_conversion.rs:21:1 | 21 | #[pyfunction] | ^^^^^^^^^^^^^ the trait `IntoPyCallbackOutput<_>` is not implemented for `Result<(), MyError>` | = help: the following implementations were found: as IntoPyCallbackOutput> note: required by a bound in `pyo3::callback::convert` --> src/callback.rs:182:8 | 182 | T: IntoPyCallbackOutput, | ^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `pyo3::callback::convert` = note: this error originates in the attribute macro `pyfunction` (in Nightly builds, run with -Z macro-backtrace for more info)