debug an exception (#638)

* debug an exception

if dst_path is not a file, it will raise Exception in the function src_path.samefile:
FileNotFoundError: [Errno 2] No such file or directory: '/home/lilongwei/notebook/onnx_diffusion/vae_decoder/model.onnx'

* Update src/diffusers/onnx_utils.py

Co-authored-by: Anton Lozhkov <[email protected]>

Author: LowinLi

src/diffusers/onnx_utils.py

@@ -79,8 +79,10 @@ def _save_pretrained(self, save_directory: Union[str, Path], file_name: Optional
 
         src_path = self.model_save_dir.joinpath(self.latest_model_name)
         dst_path = Path(save_directory).joinpath(model_file_name)
-        if not src_path.samefile(dst_path):
+        try:
             shutil.copyfile(src_path, dst_path)
+        except shutil.SameFileError:
+            pass
 
     def save_pretrained(
         self,