Struct OnErrorContext 

pub struct OnErrorContext {
    pub attempt_count: u32,
    pub task_id: TaskId,
    pub execution_context: TaskExecutionContext,
    pub state: Option<Box<dyn Any + Send + 'static>>,
}

Trait for implementing error handling policies

Error policies are lightweight, synchronous decision-makers that analyze task failures and return an ErrorResponse telling the TaskTracker what action to take. The TaskTracker handles all the actual work (cancellation, metrics, etc.) based on the policy’s response.

Key Design Principles

• Synchronous: Policies make fast decisions without async operations
• Stateless where possible: TaskTracker manages cancellation tokens and state
• Composable: Policies can be combined and nested in hierarchies
• Focused: Each policy handles one specific error pattern or strategy

Per-task error handling context

Provides context information and state management for error policies. The state field allows policies to maintain per-task state across multiple error attempts.

Fields

attempt_count: u32

Number of times this task has been attempted (starts at 1)

task_id: TaskId

Unique identifier of the failed task

execution_context: TaskExecutionContext

Full execution context with access to scheduler, metrics, etc.

state: Option<Box<dyn Any + Send + 'static>>

Optional per-task state managed by the policy (None for stateless policies)