Allow exception in hf ckpt load attempt before fallback to standard l… (NVIDIA-NeMo#14214)

* Allow exception in hf ckpt load attempt before fallback to standard load strategy

Signed-off-by: Timur Rvachov <[email protected]>

* Make exception RuntimeError specific

Signed-off-by: Timur Rvachov <[email protected]>

---------

Signed-off-by: Timur Rvachov <[email protected]>

Author: trvachov

nemo/lightning/io/api.py

@@ -266,9 +266,12 @@ def export_ckpt(
     _output_path = output_path or Path(path) / target
 
     if target == "hf":
-        modelopt_export_kwargs = modelopt_export_kwargs or {}
-        # First try to export via ModelOpt route. If rejected, return to the default route
-        output = export_hf_checkpoint(path, _output_path, **modelopt_export_kwargs)
+        try:
+            modelopt_export_kwargs = modelopt_export_kwargs or {}
+            # First try to export via ModelOpt route. If rejected, return to the default route
+            output = export_hf_checkpoint(path, _output_path, **modelopt_export_kwargs)
+        except RuntimeError:
+            output = None
         if output is not None:
             return output