fix(volumecache): normalize bytes dirs to text paths

A bytes dirs entry (e.g. dirs=b"/root/.cache") passed os.fspath unchanged,
so os.walk yielded bytes names and _is_safe_dest compared bytes against str
prefixes, raising TypeError that best-effort mode silently swallowed. Decode
each entry with os.fsdecode so all _dirs are text. Add a regression test.

Addresses review feedback on #531 (carried here as the superseding PR).

Author: deanq

runpod/serverless/utils/rp_volume_cache.py

@@ -80,7 +80,10 @@ def __init__(
             # A bare path is one directory, not an iterable of path characters:
             # `dirs="/root/.cache"` must not be split into "/", "r", "o", ...
             dirs = [dirs]
-        self._dirs = [os.path.realpath(os.fspath(d)) for d in dirs]
+        # Normalize to text paths: a bytes entry (e.g. dirs=b"...") would keep
+        # os.walk yielding bytes names and make _is_safe_dest compare bytes
+        # against str prefixes, raising TypeError that best-effort mode swallows.
+        self._dirs = [os.path.realpath(os.fsdecode(os.fspath(d))) for d in dirs]
         self._namespace = namespace or os.environ.get("RUNPOD_ENDPOINT_ID") or ""
         if self._namespace and (
             os.path.isabs(self._namespace)

tests/test_serverless/test_utils/test_rp_volume_cache.py

@@ -99,6 +99,20 @@ def test_scalar_dirs_path_is_treated_as_single_dir(tmp_path):
     assert vc_list._dirs == expected  # list input still works
 
 
+def test_bytes_dirs_are_normalized_to_text(tmp_path):
+    # A bytes path must be decoded to text; otherwise os.walk yields bytes
+    # names and _is_safe_dest compares bytes against str prefixes, raising a
+    # TypeError that best-effort mode would silently swallow.
+    vol = tmp_path / "volume"
+    vol.mkdir()
+    cache = tmp_path / "cache"
+    expected = [os.path.realpath(str(cache))]
+
+    vc_bytes = VolumeCache(str(cache).encode(), namespace="ep1", volume_path=str(vol))
+    assert vc_bytes._dirs == expected
+    assert all(isinstance(d, str) for d in vc_bytes._dirs)
+
+
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