error-handling.md

Error Handling

Accessing Errors

Each task tracks all errors that occur during execution, including retry attempts and the final failure. Errors are stored in task.errors as a list of TaskError objects.

Each TaskError contains:

Attribute	Type	Description
attempt	`int	None`
exception	str	Exception class name (e.g. "ValueError")
message	str	Error message
traceback	str	Full traceback string

Example

{* ./docs_src/errors/errors.py hl[4,16,17,20] *}

Output

Retry count: 2
Total errors: 3
  Attempt 1: [ValueError] Something went wrong
  Attempt 2: [ValueError] Something went wrong
  Attempt None: [ValueError] Something went wrong

The first two errors come from retry attempts (with attempt set). The last error is the final failure recorded by the execution engine (no attempt since it's not a retry).

Accessing the Last Error

To get only the final error:

task = workflow.result_task()[0]
if task.errors:
    last = task.errors[-1]
    print(last.message)
    print(last.exception)
    print(last.traceback)

/// warning task.error is deprecated. Use task.errors instead. ///

References

• TaskError
• Task Retry