fix: add fallback for finding bundled library when importlib.metadata unavailable

rtree/finder.py

@@ -86,6 +86,14 @@ def load() -> ctypes.CDLL:
             except importlib.metadata.PackageNotFoundError:
                 pass
 
+            # Fallback: search relative to package directory
+            # (works when importlib.metadata is unavailable, e.g. Bazel, some venvs)
+            libs_dir = _cwd.parent / "rtree.libs"
+            if libs_dir.exists():
+                for so_file in libs_dir.glob("libspatialindex*.so"):
+                    _candidates.insert(1, so_file)
+                    break
+
         for cand in _candidates:
             if cand.is_dir():
                 # if our candidate is a directory use best guess

tests/test_finder.py

@@ -1,5 +1,6 @@
 from ctypes import CDLL
 from pathlib import Path
+from unittest import mock
 
 from rtree import finder
 
@@ -9,6 +10,22 @@ def test_load():
     assert isinstance(lib, CDLL)
 
 
+def test_load_without_importlib_metadata():
+    """Test that library loading works when importlib.metadata.files() is unavailable.
+
+    This can happen in sandboxed environments like Bazel where package metadata
+    isn't properly exposed.
+    """
+    # Reload finder module with mocked importlib.metadata.files returning None
+    with mock.patch("importlib.metadata.files", return_value=None):
+        # Need to reload the module to re-run the load logic
+        import importlib
+
+        importlib.reload(finder)
+        lib = finder.load()
+        assert isinstance(lib, CDLL)
+
+
 def test_get_include():
     incl = finder.get_include()
     assert isinstance(incl, str)