From 3fe6562c570001cbb15ab6b8fa3ed7ca4e7b5434 Mon Sep 17 00:00:00 2001
From: Trenton H <797416+stumpylog@users.noreply.github.com>
Date: Fri, 24 Jul 2026 08:27:57 -0700
Subject: [PATCH] Fix: Handle a plain string as Celery sometimes provides for
 the traceback (#13267)

---
 src/documents/signals/handlers.py | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/documents/signals/handlers.py b/src/documents/signals/handlers.py
index f3ed824a2..fe1d1f94d 100644
--- a/src/documents/signals/handlers.py
+++ b/src/documents/signals/handlers.py
@@ -1264,7 +1264,17 @@ def task_failure_handler(
             "error_message": str(exception) if exception else "Unknown error",
         }
         if traceback:
-            tb_str = "".join(_tb.format_tb(traceback))
+            # billiard/celery pass a pre-formatted string instead of a real
+            # traceback object when the worker process itself died (e.g.
+            # WorkerLostError from a SIGILL) since there's no live traceback
+            # to walk in that case.
+            tb_str = (
+                traceback
+                if isinstance(traceback, str)
+                else "".join(
+                    _tb.format_tb(traceback),
+                )
+            )
             result_data["traceback"] = tb_str[:5000]
 
         now = timezone.now()