Prevent loading model for export if it is not supported (#710)

Author: eaidova

optimum/exporters/openvino/__main__.py

@@ -219,6 +219,10 @@ def main_export(
         model_type = config.model_type.replace("_", "-")
         if model_type not in TasksManager._SUPPORTED_MODEL_TYPE:
             custom_architecture = True
+            if custom_export_configs is None:
+                raise ValueError(
+                    f"Trying to export a {model_type} model, that is a custom or unsupported architecture, but no custom export configuration was passed as `custom_export_configs`. Please refer to https://huggingface.co/docs/optimum/main/en/exporters/onnx/usage_guides/export_a_model#custom-export-of-transformers-models for an example on how to export custom models. Please open an issue at https://github.com/huggingface/optimum-intel/issues if you would like the model type {model_type} to be supported natively in the OpenVINO export."
+                )
         elif task not in TasksManager.get_supported_tasks_for_model_type(
             model_type, exporter="openvino", library_name=library_name
         ):
@@ -232,6 +236,7 @@ def main_export(
             raise ValueError(
                 f"Asked to export a {model_type} model for the task {task}{autodetected_message}, but the Optimum OpenVINO exporter only supports the tasks {', '.join(model_tasks.keys())} for {model_type}. Please use a supported task. Please open an issue at https://github.com/huggingface/optimum/issues if you would like the task {task} to be supported in the ONNX export for {model_type}."
             )
+
         if is_transformers_version(">=", "4.36") and model_type in SDPA_ARCHS_ONNX_EXPORT_NOT_SUPPORTED:
             loading_kwargs["attn_implementation"] = "eager"
         # there are some difference between remote and in library representation of past key values for some models,

optimum/exporters/openvino/convert.py

@@ -547,7 +547,7 @@ def export_from_model(
     # TODO: support onnx_config.py in the model repo
     if custom_architecture and custom_export_configs is None:
         raise ValueError(
-            f"Trying to export a {model_type} model, that is a custom or unsupported architecture, but no custom export configuration was passed as `custom_export_configs`. Please refer to https://huggingface.co/docs/optimum/main/en/exporters/onnx/usage_guides/export_a_model#custom-export-of-transformers-models for an example on how to export custom models. Please open an issue at https://github.com/huggingface/optimum/issues if you would like the model type {model_type} to be supported natively in the ONNX export."
+            f"Trying to export a {model_type} model, that is a custom or unsupported architecture, but no custom export configuration was passed as `custom_export_configs`. Please refer to https://huggingface.co/docs/optimum/main/en/exporters/onnx/usage_guides/export_a_model#custom-export-of-transformers-models for an example on how to export custom models. Please open an issue at https://github.com/huggingface/optimum-intel/issues if you would like the model type {model_type} to be supported natively in the OpenVINO export."
         )
 
     if task.startswith("text-generation") and model.config.is_encoder_decoder: