Enum EngineError 

pub enum EngineError {
    LockBusy(&'static str),
    LockBusyAfterRetry(&'static str),
    BadSignature,
    TokenExpired,
    TokenUsesExhausted,
    TokenNotFound(String),
    RoleViolation {
        role: Role,
        verb: Verb,
    },
    TaskNotFound(String),
    SessionNotFound,
    ResumeKeyNotFound,
    ResourceNotFound(String),
    InvalidTransition(String),
    DispatchFailed(String),
    PollTimeout,
    Cancelled,
    SpawnDepthExceeded {
        current: u32,
        max: u32,
    },
    TokenTaskMismatch {
        bound: String,
        arg: String,
    },
    Internal(String),
}

All ways an engine operation can fail.

Variants

LockBusy(&'static str)

A required lock was busy and the operation gave up without retrying.

LockBusyAfterRetry(&'static str)

A required lock was still busy after the configured retry budget was exhausted.

BadSignature

The presented CapToken’s HMAC signature did not verify.

TokenExpired

The presented CapToken is past its expire_at.

TokenUsesExhausted

The presented CapToken has no uses left (max_uses budget spent).

TokenNotFound(String)

No server-side record exists for the token’s nonce.

RoleViolation

The token’s Role is not allow-listed for the requested Verb (see RoleVerbGate).

Fields

role: Role

The role the token was minted for.

verb: Verb

The verb that was rejected.

TaskNotFound(String)

No task exists with the given id.

SessionNotFound

No session is attached to the task.

ResumeKeyNotFound

The resume key presented does not match any pending resume point.

ResourceNotFound(String)

A generic named resource (other than task/session/token) was not found.

InvalidTransition(String)

The requested state transition is not valid from the task’s current state.

DispatchFailed(String)

Dispatching an attempt failed; the string carries the underlying reason.

PollTimeout

A poll operation exceeded its deadline without observing completion.

Cancelled

The task was cancelled.

SpawnDepthExceeded

A sub-task spawn would exceed the configured max_spawn_depth.

Fields

current: u32

The depth that would result from this spawn.

max: u32

The configured maximum allowed depth.

TokenTaskMismatch

The presented token is bound to a different task than the one referenced by the call.

Fields

bound: String

The task id the token is actually bound to.

arg: String

The task id that was passed in the call.

Internal(String)

Catch-all for invariant violations that don’t have a dedicated variant yet.

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.

impl From<EngineError> for EnhanceApplicationError

fn from(source: EngineError) -> Self

Converts to this type from the input type.

impl From<EngineError> for TaskLaunchError

fn from(source: EngineError) -> Self

Converts to this type from the input type.