Sync from kink_cli (Docker Space)

backend/user_snapshot_hub.py

@@ -13,6 +13,7 @@ from __future__ import annotations
 
 import logging
 import os
+import shutil
 from pathlib import Path
 
 logger = logging.getLogger(__name__)
@@ -82,7 +83,10 @@ def pull_user_snapshot(target_path: Path) -> bool:
     except (EntryNotFoundError, RepositoryNotFoundError):
         logger.info("snapshot %s/%s not present on Hub yet (cold start)", snapshot_repo(), snapshot_filename())
         return False
-    Path(downloaded).replace(target_path)
+    # hf_hub_download returns a path that is a symlink into the Hub blob cache with a
+    # *relative* target. ``Path.replace`` would move the symlink and break it at the
+    # new location — copy the resolved blob instead so target_path is a real file.
+    shutil.copyfile(Path(downloaded).resolve(), target_path)
     return True
 
 

tests/test_user_snapshot.py

@@ -125,3 +125,34 @@ def test_restore_is_upsert_not_destructive(store_path: Path, tmp_path: Path) ->
     assert counts.get("user", 0) >= 1
     assert _table_count(store_path, "user") == 1
     assert _table_count(store_path, "playpreference") == 1
+
+
+def test_pull_user_snapshot_resolves_relative_symlink(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
+    """hf_hub_download returns a *relative* symlink into the blob cache. Path.replace() would
+    move the symlink, breaking it at the new location and silently failing the boot-time
+    restore. pull_user_snapshot must materialise a real file via the resolved blob.
+    """
+    from unittest.mock import patch
+    from backend import user_snapshot_hub
+
+    # Build a fake Hub cache layout with a relative symlink, mirroring hf_hub_download's output.
+    cache_root = tmp_path / "hub_cache"
+    blob = cache_root / "blobs" / "abc123"
+    blob.parent.mkdir(parents=True)
+    blob.write_bytes(b"snapshot-bytes")
+    snap_dir = cache_root / "snapshots" / "rev"
+    snap_dir.mkdir(parents=True)
+    relative_symlink = snap_dir / "user_state.db"
+    relative_symlink.symlink_to(Path("../../blobs/abc123"))
+    assert relative_symlink.is_file(), "symlink resolves at original location"
+
+    target = tmp_path / "out" / "snap.db"
+
+    monkeypatch.setenv("HF_TOKEN", "tok")
+    monkeypatch.setenv("KINK_USER_SNAPSHOT_REPO", "owner/repo")
+    with patch("huggingface_hub.hf_hub_download", return_value=str(relative_symlink)):
+        ok = user_snapshot_hub.pull_user_snapshot(target)
+
+    assert ok is True
+    assert target.is_file(), "target must exist as a real file (not a broken symlink)"
+    assert target.read_bytes() == b"snapshot-bytes"