fix: fix ray lance sink error

python/python/lance/ray/sink.py

@@ -130,6 +130,37 @@ def on_write_complete(
         self,
         write_results: List[List[Tuple[str, str]]],
     ):
+        import warnings
+
+        if not write_results:
+            warnings.warn(
+                "write_results is empty.",
+                DeprecationWarning,
+            )
+            return
+        if (
+            not isinstance(write_results, list)
+            or not isinstance(write_results[0], list)
+        ) and not hasattr(write_results, "write_returns"):
+            warnings.warn(
+                "write_results type is wrong. please check version, "
+                "upgrade or downgrade your ray version. ray versions >= 2.38 "
+                "and < 2.41 are unable to write Lance datasets, check ray PR "
+                "https://github.com/ray-project/ray/pull/49251 in your "
+                "ray version. ",
+                DeprecationWarning,
+            )
+            return
+        if hasattr(write_results, "write_returns"):
+            write_results = write_results.write_returns
+
+        if len(write_results) == 0:
+            warnings.warn(
+                "write results is empty. please check ray version " "or internal error",
+                DeprecationWarning,
+            )
+            return
+
         fragments = []
         schema = None
         for batch in write_results: