On ajoute l'erreur dans les logs

src/agenda_culturel/celery.py

@@ -73,6 +73,7 @@ def close_import_task(taskid, success, error_message, importer):
 
     fields = ["status", "nb_initial", "nb_updated", "nb_imported", "nb_removed"]
     if not success:
+        logger.error(error_message)
         task.error_message = str(error_message)[:512]
         fields.append("error_message")
     task.save(update_fields=fields)