Sync pre-release CPython 3.15 branch from GitHub (2026-07-28)

Summary:
Imported python/cpython `3.15.0b4+dev` from upstream rev [`5cc8361`](https://www.github.com/python/cpython/commit/5cc8361e4baa3df705f8a811eeaeaa03e4f15b83) (committed 2026-07-28 02:30:04+00:00).

# Commit Info

- Base: (`3.15.0b4+dev`) - [`df66175`](https://www.github.com/python/cpython/commit/df66175cb819882828bb2583fb58e56ab23dc01d) (commit date: 2026-07-27 00:03:23+00:00)
- Imported: (`3.15.0b4+dev`) - [`5cc8361`](https://www.github.com/python/cpython/commit/5cc8361e4baa3df705f8a811eeaeaa03e4f15b83) (commit date: 2026-07-28 02:30:04+00:00)

# Noteworthy file changes

- Low-signal files (3 added, 1 removed) (NEWS.d, docs, .github)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GJ-ghSCGxUcJPLEDAHQmMA3TwMI9br0LAAAz

Reviewed By: itamaro

Differential Revision: D113872247

fbshipit-source-id: cbf5873566dd8a4c0bf9553877fbe7c4e5a52449

Author: generatedunixname1734921407115435

Include/internal/pycore_interp_structs.h

@@ -988,7 +988,6 @@ struct _is {
     struct _obmalloc_state *obmalloc;
 
     PyObject *audit_hooks;
-    PyMutex audit_hooks_mutex;
     PyType_WatchCallback type_watchers[TYPE_MAX_WATCHERS];
     PyCode_WatchCallback code_watchers[CODE_MAX_WATCHERS];
     PyContext_WatchCallback context_watchers[CONTEXT_MAX_WATCHERS];

Lib/asyncio/__main__.py

@@ -212,11 +212,14 @@ def interrupt(self) -> None:
     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
 
-    repl_locals = {'asyncio': asyncio}
-    for key in {'__name__', '__package__',
-                '__loader__', '__spec__',
-                '__builtins__', '__file__'}:
-        repl_locals[key] = locals()[key]
+    repl_locals = {
+        'asyncio': asyncio,
+        '__name__': __name__,
+        '__package__': None,
+        '__loader__': __loader__,
+        '__spec__': None,
+        '__builtins__': __builtins__,
+    }
 
     console = AsyncIOInteractiveConsole(repl_locals, loop)
 

Lib/collections/__init__.py

@@ -553,6 +553,9 @@ class Counter(dict):
     or multiset.  Elements are stored as dictionary keys and their counts
     are stored as dictionary values.
 
+    When constructed from a Mapping or Counter, the original object's
+    values will be used as the initial counts.
+
     >>> c = Counter('abcdeabcdabcaba')  # count elements from a string
 
     >>> c.most_common(3)                # three most common elements

Lib/sysconfig/__init__.py

@@ -437,6 +437,7 @@ def parse_config_h(fp, vars=None):
     import re
     define_rx = re.compile("#define ([A-Z][A-Za-z0-9_]+) (.*)\n")
     undef_rx = re.compile("/[*] #undef ([A-Z][A-Za-z0-9_]+) [*]/\n")
+    quoted_re = re.compile('^"(.*)"$')
 
     while True:
         line = fp.readline()
@@ -445,6 +446,8 @@ def parse_config_h(fp, vars=None):
         m = define_rx.match(line)
         if m:
             n, v = m.group(1, 2)
+            if mq := quoted_re.match(v):
+                v = mq.group(1)
             try:
                 if n in _ALWAYS_STR:
                     raise ValueError

Lib/test/test_free_threading/test_sys.py

@@ -44,20 +44,6 @@ def worker(worker_id):
         workers = [lambda: worker(i) for i in range(5)]
         threading_helper.run_concurrently(workers)
 
-    def test_sys_audit_hooks(self):
-        def _hook(*args):
-            return None
-
-        def adder():
-            for _ in range(100):
-                sys.addaudithook(_hook)
-
-        def auditor():
-            for _ in range(2000):
-                sys.audit("fusil.tsan.test")
-
-        threading_helper.run_concurrently([adder, auditor])
-
 
 if __name__ == "__main__":
     unittest.main()

Lib/test/test_functools.py

@@ -579,6 +579,40 @@ def f(**kwargs):
         with self.assertRaises(RuntimeError):
             result = p(**{BadStr("poison"): "new_value"})
 
+    def test_call_safety_against_reentrant_mutation(self):
+        def old_function(*args, **kwargs):
+            return "old_function", args, kwargs
+
+        def new_function(*args, **kwargs):
+            return "new_function", args, kwargs
+
+        g_partial = None
+
+        class EvilKey(str):
+            armed = False
+            def __hash__(self):
+                if EvilKey.armed and g_partial is not None:
+                    EvilKey.armed = False
+                    new_args_tuple = ("new_arg",)
+                    new_keywords_dict = {"new_keyword": None}
+                    new_tuple_state = (new_function, new_args_tuple, new_keywords_dict, None)
+                    g_partial.__setstate__(new_tuple_state)
+                    gc.collect()
+                return str.__hash__(self)
+
+        g_partial = functools.partial(old_function, "old_arg", old_keyword=None)
+
+        kwargs = {EvilKey("evil_key"): None}
+        EvilKey.armed = True
+
+        result = g_partial(**kwargs)
+        expected = ("old_function", ("old_arg",), {"old_keyword": None, "evil_key": None})
+        self.assertEqual(result, expected)
+
+        result = g_partial()
+        expected = ("new_function", ("new_arg",), {"new_keyword": None})
+        self.assertEqual(result, expected)
+
 @unittest.skipUnless(c_functools, 'requires the C _functools module')
 class TestPartialC(TestPartial, unittest.TestCase):
     if c_functools:

Lib/test/test_sysconfig.py

@@ -576,6 +576,12 @@ def test_linux_ext_suffix(self):
                 expected_suffixes = 'x86_64-linux-gnu.so', 'x86_64-linux-musl.so'
             self.assertEndsWith(suffix, expected_suffixes)
 
+    @unittest.skipIf(sysconfig.get_config_var('PY_BUILTIN_HASHLIB_HASHES') is None,
+                     'PY_BUILTIN_HASHLIB_HASHES required for this test')
+    def test_PY_BUILTIN_HASHLIB_HASHES_in_vars(self):
+        vars = sysconfig.get_config_vars()
+        self.assertFalse(vars['PY_BUILTIN_HASHLIB_HASHES'].startswith('"'))
+
     @unittest.skipUnless(sys.platform == 'android', 'Android-specific test')
     def test_android_ext_suffix(self):
         machine = platform.machine()

Misc/NEWS.d/next/Core_and_Builtins/2026-05-21-21-04-43.gh-issue-150208.VOkxRG.rst

@@ -0,0 +1,2 @@
+Avoid double-quoting string values from ``pyconfig.h`` in ``sysconfigdata``
+variables.

Misc/NEWS.d/next/Library/2025-10-19-17-34-07.gh-issue-140326.kZM0pV.rst

@@ -0,0 +1,3 @@
+Fix the :mod:`asyncio` REPL namespace so that relative imports no longer
+resolve against the :mod:`asyncio` package and ``__file__`` is no longer
+set.