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

Summary:
Imported python/cpython `3.15.0b3+dev` from upstream rev [`017e4e9`](https://www.github.com/python/cpython/commit/017e4e9bb8152bf09acd31b5fcaafceac002d84f) (committed 2026-07-07 00:24:44+00:00).

# Commit Info

- Base: (`3.15.0b3+dev`) - [`5ae6203`](https://www.github.com/python/cpython/commit/5ae62034e5ef8c9799f08364e06ade9064826e39) (commit date: 2026-07-05 19:36:51+00:00)
- Imported: (`3.15.0b3+dev`) - [`017e4e9`](https://www.github.com/python/cpython/commit/017e4e9bb8152bf09acd31b5fcaafceac002d84f) (commit date: 2026-07-07 00:24:44+00:00)

# Noteworthy file changes

- Low-signal files (5 added) (NEWS.d, docs, .github)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GPKyLizWhyQ2yvQEAOlaaVg1AdZ8br0LAAAz

Reviewed By: itamaro

Differential Revision: D110848646

fbshipit-source-id: 5e44f8de9bdc7b0aa264ea213c01379b2e437fb0

Author: generatedunixname1734921407115435

.github/workflows/build.yml

@@ -253,16 +253,16 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # macos-26 is Apple Silicon, macos-15-intel is Intel.
-        # macos-15-intel only runs tests against the GIL-enabled CPython.
+        # macos-26 is Apple Silicon, macos-26-intel is Intel.
+        # macos-26-intel only runs tests against the GIL-enabled CPython.
         os:
         - macos-26
-        - macos-15-intel
+        - macos-26-intel
         free-threading:
         - false
         - true
         exclude:
-        - os: macos-15-intel
+        - os: macos-26-intel
           free-threading: true
     uses: ./.github/workflows/reusable-macos.yml
     with:

.github/workflows/reusable-macos.yml

@@ -54,15 +54,15 @@ jobs:
           --prefix=/opt/python-dev \
           --with-openssl="$(brew --prefix openssl@3.5)"
     - name: Build CPython
-      if : ${{ inputs.free-threading || inputs.os != 'macos-15-intel' }}
+      if : ${{ inputs.free-threading || inputs.os != 'macos-26-intel' }}
       run: gmake -j8
     - name: Build CPython for compiler warning check
-      if : ${{ !inputs.free-threading && inputs.os == 'macos-15-intel' }}
+      if : ${{ !inputs.free-threading && inputs.os == 'macos-26-intel' }}
       run: set -o pipefail; gmake -j8 --output-sync 2>&1 | tee compiler_output_macos.txt
     - name: Display build info
       run: make pythoninfo
     - name: Check compiler warnings
-      if : ${{ !inputs.free-threading && inputs.os == 'macos-15-intel' }}
+      if : ${{ !inputs.free-threading && inputs.os == 'macos-26-intel' }}
       run: >-
         python3 Tools/build/check_warnings.py
         --compiler-output-file-path=compiler_output_macos.txt

Doc/library/glob.rst

@@ -29,7 +29,7 @@ not by actually invoking a subshell.
    The pathnames are returned in no particular order.  If you need a specific
    order, sort the results.
 
-Files beginning with a dot (``.``) can only be matched by
+By default, files beginning with a dot (``.``) can only be matched by
 patterns that also start with a dot,
 unlike :func:`fnmatch.fnmatch` or :func:`pathlib.Path.glob`.
 For tilde and shell variable expansion, use :func:`os.path.expanduser` and
@@ -70,7 +70,8 @@ The :mod:`!glob` module defines the following functions:
    pattern is followed by an :data:`os.sep` or :data:`os.altsep` then files will not
    match.
 
-   If *include_hidden* is true, "``**``" pattern will match hidden directories.
+   If *include_hidden* is true, wildcards can match path segments that
+   begin with a dot (``.``).
 
    .. audit-event:: glob.glob pathname,recursive glob.glob
    .. audit-event:: glob.glob/2 pathname,recursive,root_dir,dir_fd glob.glob
@@ -131,7 +132,7 @@ The :mod:`!glob` module defines the following functions:
    Escape all special characters (``'?'``, ``'*'`` and ``'['``).
    This is useful if you want to match an arbitrary literal string that may
    have special characters in it.  Special characters in drive/UNC
-   sharepoints are not escaped, e.g. on Windows
+   sharepoints are not escaped, for example on Windows
    ``escape('//?/c:/Quo vadis?.txt')`` returns ``'//?/c:/Quo vadis[?].txt'``.
 
    .. versionadded:: 3.4

Doc/library/os.rst

@@ -2180,6 +2180,11 @@ features:
 
    .. audit-event:: os.chdir path os.chdir
 
+   .. seealso::
+
+      The :func:`contextlib.chdir` context manager, which changes the current
+      working directory on entering and restores the previous one on exit.
+
    .. versionchanged:: 3.3
       Added support for specifying *path* as a file descriptor
       on some platforms.
@@ -3032,10 +3037,16 @@ features:
 
    .. attribute:: path
 
-      The entry's full path name: equivalent to ``os.path.join(scandir_path,
-      entry.name)`` where *scandir_path* is the :func:`scandir` *path*
-      argument.  The path is only absolute if the :func:`scandir` *path*
-      argument was absolute.  If the :func:`scandir` *path*
+      The entry's path name: equivalent to ``os.path.join(scandir_path,
+      entry.name)`` where *scandir_path* is the original :func:`scandir`
+      *path* argument.  Apart from the filename, the path preserves the
+      original :func:`scandir` argument.  If the :func:`scandir` *path*
+      argument was relative, the :attr:`path` attribute is also relative.
+      Changing the current working directory after creating the
+      :func:`scandir` iterator may cause later uses of :attr:`path` to resolve
+      differently.  On some platforms, the constructed path may not be valid
+      if the original :func:`scandir` argument was usable for enumeration but
+      not for joining with the entry name.  If the :func:`scandir` *path*
       argument was a :ref:`file descriptor <path_fd>`, the :attr:`path`
       attribute is the same as the :attr:`name` attribute.
 

Doc/library/urllib.parse.rst

@@ -60,11 +60,16 @@ or on combining URL components into a URL string.
    *missing_as_none* is true.
    Not defined component are represented an empty string (by default) or
    ``None`` if *missing_as_none* is true.
-   The components are not broken up
-   into smaller parts (for example, the network location is a single string), and %
-   escapes are not expanded. The delimiters as shown above are not part of the
-   result, except for a leading slash in the *path* component, which is retained if
-   present.  For example:
+   The delimiters as shown above are not part of the result, except for a
+   leading slash in the *path* component, which is retained if present.
+
+   Additionally, the netloc property is broken down into these additional
+   attributes added to the returned object: username, password, hostname, and
+   port.
+
+   Percent-encoded sequences are not decoded.
+
+   For example:
 
    .. doctest::
       :options: +NORMALIZE_WHITESPACE

Lib/glob.py

@@ -34,8 +34,8 @@ def glob(pathname, *, root_dir=None, dir_fd=None, recursive=False,
     If `dir_fd` is not None, it should be a file descriptor referring to a
     directory, and paths will then be relative to that directory.
 
-    If `include_hidden` is true, the patterns '*', '?', '**'  will match
-    hidden directories.
+    If `include_hidden` is true, wildcards can match path segments beginning
+    with a dot ('.').
 
     If `recursive` is true, the pattern '**' will match any files and
     zero or more directories and subdirectories.
@@ -64,8 +64,8 @@ def iglob(pathname, *, root_dir=None, dir_fd=None, recursive=False,
     If `dir_fd` is not None, it should be a file descriptor referring to a
     directory, and paths will then be relative to that directory.
 
-    If `include_hidden` is true, the patterns '*', '?', '**'  will match
-    hidden directories.
+    If `include_hidden` is true, wildcards can match path segments beginning
+    with a dot ('.').
 
     If `recursive` is true, the pattern '**' will match any files and
     zero or more directories and subdirectories.

Lib/profiling/tracing/__init__.py

@@ -197,7 +197,9 @@ def main():
             # in the module's namespace.
             globs = module.__dict__
             globs.update({
-                '__spec__': spec,
+                # Set __spec__ to None so the profiled program behaves like a
+                # script run directly (gh-140729).
+                '__spec__': None,
                 '__file__': spec.origin,
                 '__name__': spec.name,
                 '__package__': None,

Lib/test/test_capi/test_bytes.py

@@ -222,10 +222,10 @@ def test_decodeescape(self):
         self.assertEqual(decodeescape(br'x\xa\xy', 'replace'), b'x??y')
         self.assertEqual(decodeescape(br'x\xa\xy', 'ignore'), b'xy')
         self.assertRaises(ValueError, decodeescape, b'\\', 'spam')
-        self.assertEqual(decodeescape(NULL), b'')
         self.assertRaises(OverflowError, decodeescape, b'abc', NULL, PY_SSIZE_T_MAX)
         self.assertRaises(OverflowError, decodeescape, NULL, NULL, PY_SSIZE_T_MAX)
 
+        # INVALID decodeescape(NULL)
         # CRASHES decodeescape(b'abc', NULL, -1)
         # CRASHES decodeescape(NULL, NULL, 1)
 

Lib/test/test_fstring.py

@@ -1706,6 +1706,9 @@ def test_invalid_syntax_error_message(self):
         with self.assertRaisesRegex(SyntaxError,
                                     "f-string: expecting '=', or '!', or ':', or '}'"):
             compile("f'{a $ b}'", "?", "exec")
+        with self.assertRaisesRegex(SyntaxError,
+                                    "f-string: expecting '!', or ':', or '}'"):
+            compile("f'{a=b}'", "?", "exec")
 
     def test_with_two_commas_in_format_specifier(self):
         error_msg = re.escape("Cannot specify ',' with ','.")

Lib/test/test_math_integer.py

@@ -15,6 +15,19 @@ def __init__(self, value):
     def __index__(self):
         return self.value
 
+# int subclass with broken arithmetic operators; implementations must
+# convert their arguments to exact ints instead of using these.
+class BadIntSubclass(int):
+    def _binop(self, other='ignored', mod=None):
+        return 42
+    __add__ = __radd__ = __sub__ = __rsub__ = _binop
+    __mul__ = __rmul__ = __mod__ = __rmod__ = _binop
+    __divmod__ = __rdivmod__ = __pow__ = __rpow__ = _binop
+    __floordiv__ = __rfloordiv__ = _binop
+    __lshift__ = __rlshift__ = __rshift__ = __rrshift__ = _binop
+    __and__ = __rand__ = __or__ = __ror__ = __xor__ = __rxor__ = _binop
+    __lt__ = __le__ = __gt__ = __ge__ = _binop
+
 # Here's a pure Python version of the math.integer.factorial algorithm, for
 # documentation and comparison purposes.
 #
@@ -226,6 +239,11 @@ def test_isqrt(self):
         self.assertIntEqual(isqrt(False), 0)
         self.assertIntEqual(isqrt(MyIndexable(1729)), 41)
 
+        # Overridden operators of an int subclass must not affect the
+        # result.
+        self.assertIntEqual(isqrt(BadIntSubclass(10**20)), 10**10)
+        self.assertIntEqual(isqrt(BadIntSubclass(10**20 - 1)), 10**10 - 1)
+
         with self.assertRaises(ValueError):
             isqrt(MyIndexable(-3))