Only validate on macOS.

app.py

@@ -6,6 +6,8 @@ from pathlib import Path
 
 from huggingface_hub import hf_hub_download, HfApi
 from coremltools import ComputeUnit
+from coremltools.models.utils import _is_macos, _macos_version
+
 from transformers.onnx.utils import get_preprocessor
 
 from exporters.coreml import export
@@ -155,10 +157,11 @@ def convert_model(preprocessor, model, model_coreml_config,
 
     mlmodel.save(filename)
 
-    progress(progress_end * 0.8, desc=f"Validating {model_label}")
-    if tolerance is None:
-        tolerance = coreml_config.atol_for_validation
-    validate_model_outputs(coreml_config, preprocessor, model, mlmodel, tolerance)
+    if _is_macos() and _macos_version() >= (12, 0):
+        progress(progress_end * 0.8, desc=f"Validating {model_label}")
+        if tolerance is None:
+            tolerance = coreml_config.atol_for_validation
+        validate_model_outputs(coreml_config, preprocessor, model, mlmodel, tolerance)
     progress(progress_end, desc=f"Done converting {model_label}")
 
 
@@ -176,8 +179,7 @@ def push_to_hub(destination, directory, task, precision, token=None):
     )
 
     subprocess.run(["rm", "-rf", directory])
-    return f"""Successfully converted! We opened a PR to add the Core ML weights to the model repo.
-            Please, view and merge the PR [here]({get_pr_url(HfApi(token=token), destination, commit_message)})."""
+    return get_pr_url(HfApi(token=token), destination, commit_message)
 
 
 def convert(model_id, task,
@@ -249,8 +251,16 @@ def convert(model_id, task,
             )
 
         progress(0.7, "Uploading model to Hub")
-        result = push_to_hub(destination_model, base, task, precision, token=token)
+        pr_url = push_to_hub(destination_model, base, task, precision, token=token)
         progress(1, "Done")
+
+        did_validate = _is_macos() and _macos_version() >= (12, 0)
+        result = f"""### Successfully converted!
+        We opened a PR to add the Core ML weights to the model repo. Please, view and merge the PR [here]({pr_url}).
+
+        {f"**Note**: model could not be automatically validated as this Space is not running on macOS." if not did_validate else ""}
+        """
+
         return result
     except Exception as e:
         return error_str(e, model=model_id, task=task, framework=framework, compute_units=compute_units, precision=precision, tolerance=tolerance)