Enum EngineError 

pub enum EngineError {
    ThinkFailed(String),
    ProcessFailed(String),
    ContextFailed(String),
    Config(String),
    Cancelled,
}

Errors that can occur during agent engine operation.

Variants

ThinkFailed(String)

The Thinker failed to produce a response.

Defaults to retryable (transient provider failures are common). Callers may inspect the message for permanent failures.

ProcessFailed(String)

The output processor failed during processing.

Not retryable by default — usually indicates invalid input or a deterministic execution failure.

ContextFailed(String)

The context builder failed during processing.

Not retryable by default — usually indicates broken state or configuration.

Config(String)

Engine construction or configuration failed (e.g. missing thinker).

Not retryable — fix the configuration before rebuilding.

Cancelled

The engine was cancelled by the user or system.

Implementations

impl EngineError

pub fn is_retryable(&self) -> bool

Returns true if the operation can be safely retried.

Classification is conservative for structural failures and optimistic for thinker/cancellation paths:

Variant	Retryable
Cancelled	yes
ThinkFailed	yes (default; may be permanent)
ContextFailed	no
ProcessFailed	no
Config	no

Trait Implementations

impl Debug for EngineError

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

Formats the value using the given formatter.

impl Display for EngineError

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

Formats the value using the given formatter.

impl Error for EngineError

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.