Sync pre-release CPython 3.15 branch from GitHub (2026-05-22)

Summary:
Imported python/cpython `3.15.0b1+` from upstream rev [`081187f`](https://www.github.com/python/cpython/commit/081187f169556fb1b2d6a9b96f7b7e509f6ad985) (committed 2026-05-22 21:17:51+00:00).

# Commit Info

Base: (`3.15.0b1+`) - [`072246a`](https://www.github.com/python/cpython/commit/072246a7803246f562bea6d099d2c3640d59db96) (commit date: 2026-05-22 02:18:28+00:00)
Imported: (`3.15.0b1+`) - [`081187f`](https://www.github.com/python/cpython/commit/081187f169556fb1b2d6a9b96f7b7e509f6ad985) (commit date: 2026-05-22 21:17:51+00:00)

# Noteworthy file changes

- Low-signal files (4 added) (NEWS.d, docs, .github)
- Other files (1 added)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GAvaxCInS1TaaakIAByDXKrXqPUdbr0LAAAz

Differential Revision: D106166459

fbshipit-source-id: 07d725211d428757c5d7b4d80f831f57c7924727

Author: generatedunixname1734921407115435

.github/workflows/reusable-macos.yml

@@ -38,9 +38,8 @@ jobs:
       run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
     - name: Install Homebrew dependencies
       run: |
-        brew install pkg-config openssl@3.5 xz gdbm tcl-tk@9 make
-        # Because alternate versions are not symlinked into place by default:
-        brew link --overwrite tcl-tk@9
+        brew bundle --file=Misc/Brewfile
+        brew install make
     - name: Configure CPython
       run: |
         MACOSX_DEPLOYMENT_TARGET=10.15 \

Doc/c-api/sentinel.rst

@@ -31,12 +31,12 @@ Sentinel objects
 
    .. versionadded:: 3.15
 
-.. c:function:: PyObject* PySentinel_New(const char *name, const char *module_name)
+.. c:function:: PyObject* PySentinel_New(const char *name, const char *module_name, const char *repr)
 
    Return a new :class:`sentinel` object with :attr:`~sentinel.__name__` set to
    *name* and :attr:`~sentinel.__module__` set to *module_name*.
    *name* must not be ``NULL``. If *module_name* is ``NULL``, :attr:`~sentinel.__module__`
-   is set to ``None``.
+   is set to ``None``. If *repr* is ``NULL``, ``repr()`` returns :attr:`~sentinel.__name__`.
    Return ``NULL`` with an exception set on failure.
 
    For pickling to work, *module_name* must be the name of an importable

Doc/data/python3.15.abi

@@ -2040,6 +2040,7 @@ PySeqIter_New:PyObject*:seq:0:
 PySentinel_New:PyObject*::+1:
 PySentinel_New:const char*:name::
 PySentinel_New:const char*:module_name::
+PySentinel_New:const char*:repr::
 
 PySequence_Check:int:::
 PySequence_Check:PyObject*:o:0:

Doc/data/refcounts.dat

@@ -728,18 +728,16 @@ Finally, we compare the two:
 
    >>> from pprint import pprint
    >>> pprint(result)
-   [
-       '    1. Beautiful is better than ugly.\n',
-       '-   2. Explicit is better than implicit.\n',
-       '-   3. Simple is better than complex.\n',
-       '+   3.   Simple is better than complex.\n',
-       '?     ++\n',
-       '-   4. Complex is better than complicated.\n',
-       '?            ^                     ---- ^\n',
-       '+   4. Complicated is better than complex.\n',
-       '?           ++++ ^                      ^\n',
-       '+   5. Flat is better than nested.\n',
-   ]
+   ['    1. Beautiful is better than ugly.\n',
+    '-   2. Explicit is better than implicit.\n',
+    '-   3. Simple is better than complex.\n',
+    '+   3.   Simple is better than complex.\n',
+    '?     ++\n',
+    '-   4. Complex is better than complicated.\n',
+    '?            ^                     ---- ^\n',
+    '+   4. Complicated is better than complex.\n',
+    '?           ++++ ^                      ^\n',
+    '+   5. Flat is better than nested.\n']
 
 As a single multi-line string it looks like this:
 

Doc/library/difflib.rst

@@ -1827,15 +1827,21 @@ are always available.  They are listed here in alphabetical order.
       :func:`setattr`.
 
 
-.. class:: sentinel(name, /)
+.. class:: sentinel(name, /, *, repr=None)
 
    Return a new unique sentinel object.  *name* must be a :class:`str`, and is
-   used as the returned object's representation::
+   used by default as the returned object's representation::
 
       >>> MISSING = sentinel("MISSING")
       >>> MISSING
       MISSING
 
+   The optional *repr* argument can be used to specify a different representation::
+
+      >>> MISSING = sentinel("MISSING", repr="<MISSING>")
+      >>> MISSING
+      <MISSING>
+
    Sentinel objects are truthy and compare equal only to themselves.  They are
    intended to be compared with the :keyword:`is` operator.
 
@@ -1879,7 +1885,7 @@ are always available.  They are listed here in alphabetical order.
 
    .. attribute:: __module__
 
-      The name of the module where the sentinel was created.
+      The name of the module where the sentinel was created. This attribute is writable.
 
    .. versionadded:: 3.15
 

Doc/library/functions.rst

@@ -108,9 +108,13 @@ The module defines the following items:
    is no compression. The default is ``9``.
 
    The optional *mtime* argument is the timestamp requested by gzip. The time
-   is in Unix format, i.e., seconds since 00:00:00 UTC, January 1, 1970.
-   If *mtime* is omitted or ``None``, the current time is used. Use *mtime* = 0
-   to generate a compressed stream that does not depend on creation time.
+   is in Unix format, i.e., seconds since 00:00:00 UTC, January 1, 1970. Set
+   *mtime* to ``0`` to generate a compressed stream that does not depend on
+   creation time. If *mtime* is omitted or ``None``, the current time is used;
+   however, if the current time is outside the range 00:00:00 UTC, January 1,
+   1970 through 06:28:15 UTC, February 7, 2106, or explicitly passed *mtime*
+   argument is outside the range ``0`` to ``2**32-1``, then the value ``0``
+   is used instead.
 
    See below for the :attr:`mtime` attribute that is set when decompressing.