chore: import upstream snapshot with attribution

nemo/utils/file_utils.py

@@ -0,0 +1,31 @@
+# Copyright (c) 2025, NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import shutil
+from pathlib import Path
+from typing import Union
+
+
+def robust_copy(src: Union[Path, str], dst: Union[Path, str]) -> str:
+    """
+    Copy file from src to dst, falling back to shutil.copy if shutil.copy2 fails.
+    shutil.copy2 preserves metadata, but can fail on some filesystems.
+    """
+    try:
+        return shutil.copy2(src, dst)
+    except PermissionError:
+        # copy2 can fail on some filesystems due to metadata copy errors
+        # (e.g., permission errors on setting timestamps).
+        # In such cases, we fallback to a plain copy.
+        return shutil.copy(src, dst)