Align JSON array hooks and libraries with Python 3.15 (#9135)

Generate the JSON library and selected tests with update_lib from CPython d220409a13b77de7a6c30abe16ea90db01528edc, preserving native bootstrap workarounds and test markers. Exclude generated cache directories at the library copy boundary.

Assisted-by: OpenAI Codex:model version unavailable

scripts/update_lib/cmd_copy_lib.py

@@ -16,6 +16,14 @@ import shutil
 import sys
 
 
+def _ignore_bytecode_caches(directory: str, names: list[str]) -> set[str]:
+    return {
+        name
+        for name in names
+        if name == "__pycache__" and (pathlib.Path(directory) / name).is_dir()
+    }
+
+
 def _copy_single(
     src_path: pathlib.Path,
     lib_path: pathlib.Path,
@@ -38,7 +46,7 @@ def _copy_single(
         if verbose:
             print(f"Copying directory: {src_path} -> {lib_path}")
         lib_path.parent.mkdir(parents=True, exist_ok=True)
-        shutil.copytree(src_path, lib_path)
+        shutil.copytree(src_path, lib_path, ignore=_ignore_bytecode_caches)
     else:
         if verbose:
             print(f"Copying file: {src_path} -> {lib_path}")

scripts/update_lib/tests/test_copy_lib.py

@@ -57,6 +57,45 @@ class TestCopySingle(unittest.TestCase):
 
             self.assertEqual(dst.read_text(), "new content")
 
+    def test_directory_copy_excludes_bytecode_cache_directories(self):
+        from update_lib.cmd_copy_lib import _copy_single
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            root = pathlib.Path(tmpdir)
+            src = root / "source"
+            dst = root / "destination"
+            for relative in ("__pycache__", "package/__pycache__", "assets"):
+                (src / relative).mkdir(parents=True)
+            files = {
+                "__init__.py": b"source\n",
+                "package/module.py": b"nested source\n",
+                "assets/data.bin": b"\x00\xffasset",
+                "assets/__pycache__": b"ordinary file, not a directory",
+                "assets/fixture.pyc": b"canonical bytecode fixture",
+                "__pycache__/module.cpython-315.pyc": b"stale cache",
+                "package/__pycache__/module.cpython-315.pyc": b"nested cache",
+            }
+            for relative, content in files.items():
+                (src / relative).write_bytes(content)
+
+            _copy_single(src, dst, verbose=False)
+
+            expected = {
+                relative: content
+                for relative, content in files.items()
+                if "__pycache__" not in pathlib.Path(relative).parts[:-1]
+            }
+            actual = {
+                path.relative_to(dst).as_posix(): path.read_bytes()
+                for path in dst.rglob("*")
+                if path.is_file()
+            }
+            self.assertEqual(actual, expected)
+            self.assertFalse((dst / "__pycache__").exists())
+            self.assertFalse((dst / "package/__pycache__").exists())
+            for relative, content in files.items():
+                self.assertEqual((src / relative).read_bytes(), content)
+
 
 class TestCopyLib(unittest.TestCase):
     """Tests for copy_lib function."""