Merge pull request #2558 from langchain-ai/nc/27nov/exc-note

lib: Add exception note identify node/task

libs/langgraph/langgraph/pregel/algo.py

@@ -1,3 +1,4 @@
+import sys
 from collections import defaultdict, deque
 from functools import partial
 from hashlib import sha1
@@ -66,6 +67,7 @@ from langgraph.types import All, LoopProtocol, PregelExecutableTask, PregelTask
 from langgraph.utils.config import merge_configs, patch_config
 
 GetNextVersion = Callable[[Optional[V], BaseChannel], V]
+SUPPORTS_EXC_NOTES = sys.version_info >= (3, 11)
 
 
 class WritesProtocol(Protocol):
@@ -634,6 +636,12 @@ def prepare_single_task(
                 )
             except StopIteration:
                 return
+            except Exception as exc:
+                if SUPPORTS_EXC_NOTES:
+                    exc.add_note(
+                        f"Before task with name '{name}' and path '{task_path[:3]}'"
+                    )
+                raise
 
             # create task id
             checkpoint_ns = f"{parent_ns}{NS_SEP}{name}" if parent_ns else name

libs/langgraph/langgraph/pregel/retry.py

@@ -1,6 +1,7 @@
 import asyncio
 import logging
 import random
+import sys
 import time
 from dataclasses import replace
 from functools import partial
@@ -18,6 +19,7 @@ from langgraph.types import Command, PregelExecutableTask, RetryPolicy
 from langgraph.utils.config import patch_configurable
 
 logger = logging.getLogger(__name__)
+SUPPORTS_EXC_NOTES = sys.version_info >= (3, 11)
 
 
 def run_with_retry(
@@ -60,6 +62,8 @@ def run_with_retry(
             # if interrupted, end
             raise
         except Exception as exc:
+            if SUPPORTS_EXC_NOTES:
+                exc.add_note(f"During task with name '{task.name}' and id '{task.id}'")
             if retry_policy is None:
                 raise
             # increment attempts
@@ -152,6 +156,8 @@ async def arun_with_retry(
             # if interrupted, end
             raise
         except Exception as exc:
+            if SUPPORTS_EXC_NOTES:
+                exc.add_note(f"During task with name '{task.name}' and id '{task.id}'")
             if retry_policy is None:
                 raise
             # increment attempts