Can I use #[pyclass(extends=PyException)] with features = ["abi3", "abi3-py39"]? How can I tell?

[thomasballinger]

I have code like

#[pyclass(extends=PyException)]
pub struct ConvexError {
    #[pyo3(get)]
    pub message: Py<PyString>,
    #[pyo3(get)]
    pub data: PyObject,
}

which works compiles without features = ["abi3", "abi3-py39"] but gives this error with it:

error[E0277]: the trait bound `PyException: PyClass` is not satisfied
   --> crates/py_client/src/client/mod.rs:298:19
    |
298 | #[pyclass(extends=PyException)]
    |                   ^^^^^^^^^^^ the trait `PyClass` is not implemented for `PyException`
    |
    = help: the following other types implement trait `PyClass`:
              PyConvexClient
              client::ConvexError
              PyQuerySubscription
              PySubscriberId
              PyQuerySetSubscription
    = note: required for `PyException` to implement `PyClassBaseType`
note: required by a bound in `PyClassImpl::BaseType`
   --> /Users/tomb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/pyo3-0.19.1/src/impl_/pyclass.rs:160:33
    |
160 |     type BaseType: PyTypeInfo + PyClassBaseType;
    |                                 ^^^^^^^^^^^^^^^ required by this bound in `PyClassImpl::BaseType`

Presumably this is a feature I cannot use because of the more limited common ABI.

Does that sound right, that that's probably the issue? How can I tell what features of py03 abi3 prevents me from using?

[davidhewitt]

Sadly this falls under #1344, which I simply haven't gotten around to tackling yet. One day, this should be possible.

[thomasballinger]

Thanks for confirming!