error[E0277]: `Rc` cannot be sent between threads safely --> tests/ui/pyclass_send.rs:4:1 | 4 | #[pyclass] | ^^^^^^^^^^ `Rc` cannot be sent between threads safely | = help: within `NotThreadSafe`, the trait `Send` is not implemented for `Rc` note: required because it appears within the type `NotThreadSafe` --> tests/ui/pyclass_send.rs:5:8 | 5 | struct NotThreadSafe { | ^^^^^^^^^^^^^ note: required by a bound in `ThreadCheckerStub` --> src/impl_/pyclass.rs | | pub struct ThreadCheckerStub(PhantomData); | ^^^^ required by this bound in `ThreadCheckerStub` = note: this error originates in the attribute macro `pyclass` (in Nightly builds, run with -Z macro-backtrace for more info)