diff --git a/src/api/toolchain_routes.py b/src/api/toolchain_routes.py
index 89d9c1a..13b746e 100644
--- a/src/api/toolchain_routes.py
+++ b/src/api/toolchain_routes.py
@@ -426,7 +426,8 @@ async def gitea_webhook(
 
     # 1. 签名验证
     if not _verify_signature(body, x_gitea_signature):
-        logger.warning("Webhook signature verification failed")
+        logger.warning("Webhook signature verification failed (has_signature=%s, expected_prefix=%s)",
+                     bool(x_gitea_signature), _WEBHOOK_SECRET[:8] if _WEBHOOK_SECRET else "none")
         return Response(status_code=403, content="signature verification failed")
 
     # 2. 幂等检查