fix ci (#12760)

sgl-router/py_test/conftest.py

@@ -1,8 +1,15 @@
 import sys
+from importlib.util import find_spec
 from pathlib import Path
 
-# Ensure local sources in py_src are importable ahead of any installed package
+# Only add py_src to path if the wheel is not installed (for local development)
+# This ensures CI tests use the installed wheel which contains the Rust extension
 _ROOT = Path(__file__).resolve().parents[1]
 _SRC = _ROOT / "py_src"
-if str(_SRC) not in sys.path:
+
+# Check if sglang_router is already installed with the Rust extension
+_wheel_installed = find_spec("sglang_router.sglang_router_rs") is not None
+
+# Only add py_src if wheel is not installed (development mode)
+if not _wheel_installed and str(_SRC) not in sys.path:
     sys.path.insert(0, str(_SRC))