fix: resolve HF symlinks in from_hub via temp local_dir

mellea/backends/adapters/adapter.py

@@ -18,6 +18,7 @@
 import contextlib
 import pathlib
 import re
+import tempfile
 import warnings
 from typing import Literal, TypeAlias, TypeVar, cast
 
@@ -751,8 +752,18 @@ def from_hub(
     ) -> list["EmbeddedIntrinsicAdapter"]:
         """Load embedded adapters from a Granite Switch model on Hugging Face Hub.
 
-        Downloads `adapter_index.json` and the `io_configs/` directory, then
-        delegates to :meth:`from_model_directory`.
+        Downloads `adapter_index.json` and the `io_configs/` directory into a
+        self-contained local directory, then delegates to
+        :meth:`from_model_directory`.
+
+        `huggingface_hub.snapshot_download`'s default cache-backed snapshot
+        directory populates `io_configs/` with symlinks that resolve into a
+        sibling `blobs/` directory *outside* the snapshot root. That breaks the
+        contract `from_model_directory` expects (a self-contained model
+        directory) and trips its path-escape check. To satisfy that contract,
+        the files are downloaded directly into a temporary directory (via
+        `local_dir`) instead, so `io_configs/` contains real files rather than
+        symlinks escaping the directory.
 
         Args:
             repo_id (str): Hugging Face Hub repository ID
@@ -780,22 +791,24 @@ def from_hub(
                 'Hugging Face Hub. Please install it with: pip install "mellea[switch]"'
             ) from e
 
-        local_root = huggingface_hub.snapshot_download(
-            repo_id=repo_id,
-            allow_patterns=["adapter_index.json", "io_configs/**"],
-            cache_dir=cache_dir,
-            revision=revision,
-        )
-        try:
-            return EmbeddedIntrinsicAdapter.from_model_directory(
-                local_root, intrinsic_name=intrinsic_name
+        with tempfile.TemporaryDirectory() as local_dir:
+            downloaded_dir = huggingface_hub.snapshot_download(
+                repo_id=repo_id,
+                allow_patterns=["adapter_index.json", "io_configs/**"],
+                cache_dir=cache_dir,
+                local_dir=local_dir,
+                revision=revision,
             )
-        except ValueError as e:
-            if intrinsic_name is not None:
-                raise ValueError(
-                    f"No adapter found for adapter function '{intrinsic_name}' in {repo_id}"
-                ) from e
-            raise ValueError(f"No adapters found in {repo_id}") from e
+            try:
+                return EmbeddedIntrinsicAdapter.from_model_directory(
+                    downloaded_dir, intrinsic_name=intrinsic_name
+                )
+            except ValueError as e:
+                if intrinsic_name is not None:
+                    raise ValueError(
+                        f"No adapter found for adapter function '{intrinsic_name}' in {repo_id}"
+                    ) from e
+                raise ValueError(f"No adapters found in {repo_id}") from e
 
     @staticmethod
     def from_source(

test/backends/test_adapters/test_embedded_adapter.py

@@ -6,7 +6,7 @@
 import json
 import os
 import pathlib
-from unittest.mock import MagicMock, patch
+from unittest.mock import ANY, MagicMock, patch
 
 import pytest
 import yaml
@@ -308,6 +308,7 @@ def test_downloads_and_delegates(self, model_dir):
             repo_id="ibm-granite/granite-switch-micro",
             allow_patterns=["adapter_index.json", "io_configs/**"],
             cache_dir="/tmp/test-cache",
+            local_dir=ANY,
             revision="test-rev",
         )
         assert len(adapters) == 2
@@ -324,11 +325,21 @@ def test_filter_single_intrinsic(self, model_dir):
             repo_id="ibm-granite/granite-switch-micro",
             allow_patterns=["adapter_index.json", "io_configs/**"],
             cache_dir=None,
+            local_dir=ANY,
             revision="main",
         )
         assert len(adapters) == 1
         assert adapters[0].intrinsic_name == "citations"
 
+    def test_from_hub_requests_local_dir(self, model_dir):
+        """from_hub requests local_dir to avoid symlinks escaping model directory."""
+        with patch(
+            "huggingface_hub.snapshot_download", return_value=str(model_dir)
+        ) as mock_dl:
+            EmbeddedIntrinsicAdapter.from_hub("ibm-granite/granite-switch-micro")
+        _, kwargs = mock_dl.call_args
+        assert "local_dir" in kwargs and kwargs["local_dir"] is not None
+
     def test_missing_huggingface_hub_raises(self):
         with patch.dict("sys.modules", {"huggingface_hub": None}):
             with pytest.raises(ImportError, match="huggingface_hub is required"):
@@ -377,6 +388,7 @@ def test_hub_passes_revision_and_cache(self, model_dir):
             repo_id="ibm-granite/granite-switch-micro",
             allow_patterns=["adapter_index.json", "io_configs/**"],
             cache_dir="/tmp/cache",
+            local_dir=ANY,
             revision="v2",
         )