fix: implement create_user_task workaround

src/ol_openedx_course_export/app.py

@@ -31,3 +31,9 @@ class CourseExportConfig(AppConfig):
             }
         },
     }
+
+    def ready(self):
+        """
+        Import signals to enable celery task protocol workaround
+        """
+        import ol_openedx_course_export.signals  # noqa: F401

src/ol_openedx_course_export/signals.py

@@ -0,0 +1,64 @@
+"""
+Signal handlers for the ol_openedx_course_export app.
+
+This module implements a workaround for a compatibility issue between django-user-tasks
+and Celery's protocol version 2. The create_user_task signal handler expects protocol
+version 1 format but receives version 2, causing TypeError exceptions in the logs.
+
+This fix wraps the original handler, converts protocol v2 messages to v1 format, and
+ensures UserTask-based tasks work properly without generating errors.
+"""
+
+from celery import chain, signals
+from cms.celery import APP
+from user_tasks.signals import create_user_task
+
+signals.before_task_publish.disconnect(create_user_task)
+
+
+def create_user_task_wrapper(sender=None, body=None, **kwargs):
+    return create_user_task(
+        sender,
+        body
+        if APP.conf.task_protocol == 1
+        else proto2_to_proto1(body, kwargs.get("headers", {})),
+    )
+
+
+signals.before_task_publish.connect(create_user_task_wrapper)
+
+
+def proto2_to_proto1(body, headers):
+    args, kwargs, embed = body
+    embedded = _extract_proto2_embed(**embed)
+    chained = embedded.pop("chain")
+    new_body = dict(
+        _extract_proto2_headers(**headers), args=args, kwargs=kwargs, **embedded
+    )
+    if chained:
+        new_body["callbacks"].append(chain(chained))
+    return new_body
+
+
+def _extract_proto2_headers(  # noqa: PLR0913
+    task_id, retries, eta, expires, group, timelimit, task, **_
+):
+    return {
+        "id": task_id,
+        "task": task,
+        "retries": retries,
+        "eta": eta,
+        "expires": expires,
+        "utc": True,
+        "taskset": group,
+        "timelimit": timelimit,
+    }
+
+
+def _extract_proto2_embed(callbacks, errbacks, chain, chord, **_):
+    return {
+        "callbacks": callbacks or [],
+        "errbacks": errbacks,
+        "chain": chain,
+        "chord": chord,
+    }