Enum DispatchError 

#[non_exhaustive]
pub enum DispatchError {
    BackendError {
        name: String,
        message: String,
    },
    UpstreamCancelled,
    MissingDependency {
        name: &'static str,
    },
    ChannelClosed,
}

Closed catalog of dispatcher errors. Adopter-reachable error surfaces are NAMED (D7 mandate: zero unwrap() / zero unimplemented!() / zero _ => catch-all). Each variant carries adopter-actionable structured data.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

BackendError

Backend::stream() failed on a per-variant handler that invoked it. Carries the backend name + the upstream error message so the SSE handler can surface a structured axon.error event.

Fields

name: String

message: String

UpstreamCancelled

Cancellation flag fired mid-dispatch (client disconnected or upstream tokio::select! raced the cancel branch). Caller MUST treat this as a clean exit (no axon.error event surfaced — the consumer is already gone).

MissingDependency

A per-variant handler needed a dependency that wasn’t available on the DispatchCtx (e.g., PEM async surface for a Remember/Recall handler before 33.y.f wires it in). The name field tags which dependency.

Fields

name: &'static str

ChannelClosed

The mpsc sender returned Err(_) — consumer dropped. Caller MUST treat this as a clean exit (same posture as UpstreamCancelled).

Trait Implementations

impl Clone for DispatchError

fn clone(&self) -> DispatchError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DispatchError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for DispatchError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for DispatchError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.