You'll noticeTier: how much it should matter to you
3Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
WorkflowsArea: what it touches
Bug FixesKind: in v2.1.285,
Bug FixesSection of the release
What
Workflow scripts can call agent(), parallel(), pipeline() and workflow(). Each call hands back a promise, a placeholder for a result that arrives later. If one of those calls fails and the script never deals with the failure, Claude Code now logs "Workflow: swallowed an unhandled rejection (not exiting)" and keeps running instead of exiting.
Why
A forgotten failure in a workflow script no longer takes down the whole process. Look for that log line if a step seems to vanish silently.
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtWhether the handler also catches unhandled failures from outside workflow scripts is not settled.
Anthropic's release notes agreeFixed a failed agent(), parallel() or pipeline() call that a workflow script awaits later, or not at all, being treated as an unhandled…
