Make download code robust to symlinks.

coremltools seems to not like symlinks.

README.md

@@ -46,18 +46,37 @@ Python | macOS | Xcode | iPadOS, iOS |
 
 If you want to use any of those models you may download the weights and proceed to [generate images with Python](#image-generation-with-python) or [Swift](#image-generation-with-swift).
 
-There are several variants in each model repository. You may clone the whole repos using `git` and `git lfs`, or select just the variants you need. For example, to do generation in Python using the `ORIGINAL` attention implementation (read [this section](#converting-models-to-core-ml) for details), you could do something like this:
+There are several variants in each model repository. You may clone the whole repos using `git` and `git lfs`, or select just the variants you need. For example, to do generation in Python using the `ORIGINAL` attention implementation (read [this section](#converting-models-to-core-ml) for details), you could use the following helper code:
 
 ```Python
 from huggingface_hub import snapshot_download
+from huggingface_hub.file_download import repo_folder_name
+from pathlib import Path
+import shutil
 
 repo_id = "apple/coreml-stable-diffusion-v1-4"
 variant = "original/packages"
 
-downloaded = snapshot_download(repo_id, allow_patterns=f"{variant}/*")
+def download_model(repo_id, variant, output_dir):
+    destination = Path(output_dir) / (repo_id.split("/")[-1] + "_" + variant.replace("/", "_"))
+    if destination.exists():
+        raise Exception(f"Model already exists at {destination}")
+    
+    # Download and copy without symlinks
+    downloaded = snapshot_download(repo_id, allow_patterns=f"{variant}/*", cache_dir=output_dir)
+    downloaded_bundle = Path(downloaded) / variant
+    shutil.copytree(downloaded_bundle, destination)
+
+    # Remove all downloaded files
+    cache_folder = Path(output_dir) / repo_folder_name(repo_id=repo_id, repo_type="model")
+    shutil.rmtree(cache_folder)
+    return destination
+
+model_path = download_model(repo_id, variant, output_dir="./models")
+print(f"Model downloaded at {model_path}")
 ```
 
-`downloaded` would be the path in your local filesystem where the model checkpoint was saved. Please, refer to [this post](https://huggingface.co/blog/diffusers-coreml) for additional details on this process.
+`model_path` would be the path in your local filesystem where the checkpoint was saved. Please, refer to [this post](https://huggingface.co/blog/diffusers-coreml) for additional details on this process.
 
 
 If you prefer to use `git` to clone the repos with all the variants, you need to follow this process: