error: Use `#[ruma_api(body)]` to represent the JSON body as a single field
  --> tests/it/api/ui/serde-flatten-response-body.rs:26:5
   |
26 | /     #[serde(flatten)]
27 | |     pub foo: CustomResponseBody,
   | |_______________________________^

error[E0277]: the trait bound `Response: IncomingResponse` is not satisfied
  --> tests/it/api/ui/serde-flatten-response-body.rs:21:1
   |
21 | #[request]
   | ^^^^^^^^^^ the trait `IncomingResponse` is not implemented for `Response`
   |
note: required by a bound in `ruma_common::api::OutgoingRequest::IncomingResponse`
  --> src/api.rs
   |
   |     type IncomingResponse: IncomingResponse<EndpointError = Self::EndpointError>;
   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `OutgoingRequest::IncomingResponse`
   = note: this error originates in the derive macro `::ruma_common::exports::ruma_macros::Request` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `Response: OutgoingResponse` is not satisfied
  --> tests/it/api/ui/serde-flatten-response-body.rs:21:1
   |
21 | #[request]
   | ^^^^^^^^^^ the trait `OutgoingResponse` is not implemented for `Response`
   |
   = help: the trait `OutgoingResponse` is implemented for `MatrixError`
note: required by a bound in `ruma_common::api::IncomingRequest::OutgoingResponse`
  --> src/api.rs
   |
   |     type OutgoingResponse: OutgoingResponse;
   |                            ^^^^^^^^^^^^^^^^ required by this bound in `IncomingRequest::OutgoingResponse`
   = note: this error originates in the derive macro `::ruma_common::exports::ruma_macros::Request` (in Nightly builds, run with -Z macro-backtrace for more info)