fix: improve error handling for HumanFeedbackPending in flow execution (#4203)

* fix: handle HumanFeedbackPending in flow error management

Updated the flow error handling to treat HumanFeedbackPending as expected control flow rather than an error. This change ensures that the flow can appropriately manage human feedback scenarios without signaling an error, improving the robustness of the flow execution.

* fix: improve error handling for HumanFeedbackPending in flow execution

Refined the flow error management to emit a paused event for HumanFeedbackPending exceptions instead of treating them as failures. This enhancement allows the flow to better manage human feedback scenarios, ensuring that the execution state is preserved and appropriately handled without signaling an error. Regular failure events are still emitted for other exceptions, maintaining robust error reporting.

Author: joaomdmoura

lib/crewai/src/crewai/flow/flow.py

@@ -1602,29 +1602,45 @@ async def _execute_method(
 
             return result
         except Exception as e:
-            if not self.suppress_flow_events:
-                # Check if this is a HumanFeedbackPending exception (paused, not failed)
-                from crewai.flow.async_feedback.types import HumanFeedbackPending
+            # Check if this is a HumanFeedbackPending exception (paused, not failed)
+            from crewai.flow.async_feedback.types import HumanFeedbackPending
 
-                if isinstance(e, HumanFeedbackPending):
-                    # Auto-save pending feedback (create default persistence if needed)
-                    if self._persistence is None:
-                        from crewai.flow.persistence import SQLiteFlowPersistence
+            if isinstance(e, HumanFeedbackPending):
+                # Auto-save pending feedback (create default persistence if needed)
+                if self._persistence is None:
+                    from crewai.flow.persistence import SQLiteFlowPersistence
 
-                        self._persistence = SQLiteFlowPersistence()
+                    self._persistence = SQLiteFlowPersistence()
 
-            # Regular failure
-            future = crewai_event_bus.emit(
-                self,
-                MethodExecutionFailedEvent(
-                    type="method_execution_failed",
-                    method_name=method_name,
-                    flow_name=self.name or self.__class__.__name__,
-                    error=e,
-                ),
-            )
-            if future:
-                self._event_futures.append(future)
+                # Emit paused event (not failed)
+                if not self.suppress_flow_events:
+                    future = crewai_event_bus.emit(
+                        self,
+                        MethodExecutionPausedEvent(
+                            type="method_execution_paused",
+                            method_name=method_name,
+                            flow_name=self.name or self.__class__.__name__,
+                            state=self._copy_and_serialize_state(),
+                            flow_id=e.context.flow_id,
+                            message=e.context.message,
+                            emit=e.context.emit,
+                        ),
+                    )
+                    if future:
+                        self._event_futures.append(future)
+            elif not self.suppress_flow_events:
+                # Regular failure - emit failed event
+                future = crewai_event_bus.emit(
+                    self,
+                    MethodExecutionFailedEvent(
+                        type="method_execution_failed",
+                        method_name=method_name,
+                        flow_name=self.name or self.__class__.__name__,
+                        error=e,
+                    ),
+                )
+                if future:
+                    self._event_futures.append(future)
             raise e
 
     def _copy_and_serialize_state(self) -> dict[str, Any]: