Add Python 3.15 test infrastructure

python · srittau · May 13, 2026 · May 7, 2026 · May 7, 2026 · May 7, 2026
commit 44d2e5686c4af75240b17fdb56e74af5f0ad619c
diff --git a/.github/workflows/daily.yml b/.github/workflows/daily.yml
@@ -35,7 +35,7 @@ jobs:
     strategy:
       matrix:
         os: ["ubuntu-latest", "windows-latest", "macos-latest"]
-        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "3.15"]
         exclude:
           # https://github.com/python/typeshed/issues/15694
           - os: "windows-latest"

diff --git a/.github/workflows/stubtest_stdlib.yml b/.github/workflows/stubtest_stdlib.yml
@@ -31,7 +31,7 @@ jobs:
     strategy:
       matrix:
         os: ["ubuntu-latest", "windows-latest", "macos-latest"]
-        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "3.15"]
         exclude:
           # https://github.com/python/typeshed/issues/15694
           - os: "windows-latest"

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
@@ -42,7 +42,7 @@ jobs:
     strategy:
       matrix:
         platform: ["linux", "win32", "darwin"]
-        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "3.15"]
       fail-fast: false
     steps:
       - uses: actions/checkout@v6
@@ -71,7 +71,9 @@ jobs:
       - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
-          python-version: "3.14"
+          python-version: "3.15"
+          allow-prereleases: true
+          check-latest: true
       - uses: astral-sh/setup-uv@v7
         with:
           version-file: "requirements-tests.txt"
@@ -83,6 +85,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
+        # TODO: Add 3.15 once pyright CI can avoid installing third-party
+        # runtime dependency stacks that do not support Python 3.15 yet.
         python-platform: ["Linux", "Windows", "Darwin"]
         python-version: ["3.11", "3.12", "3.13", "3.14"]
       fail-fast: false

diff --git a/lib/ts_utils/py315.py b/lib/ts_utils/py315.py
@@ -0,0 +1,20 @@
+"""Helpers for Python 3.15 test infrastructure."""
+
+# These stubs require runtime dependencies that do not install cleanly on Python 3.15 yet.
+PY315_INCOMPATIBLE_RUNTIME_DEPENDENCIES = {
+    # Depend on numpy, which does not provide Python 3.15 wheels yet.
+    "JACK-Client",
+    "geopandas",
+    "hnswlib",
+    "networkx",
+    "pycocotools",
+    "resampy",
+    "shapely",
+    "tensorflow",
+    # Depends on referencing, which depends on rpds-py. rpds-py currently uses
+    # PyO3, which rejects Python 3.15.
+    "jsonschema",
+    # Depends on matplotlib, which depends on contourpy. contourpy does not
+    # provide Python 3.15 wheels yet.
+    "seaborn",
+}
diff --git a/requirements-tests.txt b/requirements-tests.txt
@@ -5,14 +5,15 @@ pyright==1.1.409
 
 # Libraries used by our various scripts.
 aiohttp==3.13.5
-grpcio-tools>=1.76.0 # For grpc_tools.protoc
-mypy-protobuf==5.0.0
+grpcio-tools>=1.76.0; python_version < "3.15" # For grpc_tools.protoc
+mypy-protobuf==5.0.0; python_version < "3.15"
 packaging==26.0
 pathspec>=1.1.1
 pre-commit
-# Required by create_baseline_stubs.py. Must match .pre-commit-config.yaml.
+# Required by create_baseline_stubs.py.
+# stubdefaulter depends on libcst, which does not yet install cleanly on Python 3.15.
 ruff==0.15.8
-stubdefaulter==0.1.0
+stubdefaulter==0.1.0; python_version < "3.15"
 termcolor>=2.3
 tomli==2.4.1; python_version < "3.11"
 tomlkit==0.14.0

diff --git a/scripts/sync_protobuf/_utils.py b/scripts/sync_protobuf/_utils.py
@@ -4,19 +4,21 @@
 import sys
 from collections.abc import Iterable
 from http.client import HTTPResponse
+from importlib.metadata import PackageNotFoundError, version
 from pathlib import Path
 from typing import TYPE_CHECKING
 from urllib.request import urlopen
 from zipfile import ZipFile
 
-from mypy_protobuf.main import (  # type: ignore[import-untyped]  # pyright: ignore[reportMissingTypeStubs]
-    __version__ as mypy_protobuf__version__,
-)
+try:
+    _mypy_protobuf_version = version("mypy-protobuf")
+except PackageNotFoundError:
+    _mypy_protobuf_version = "unavailable"
 
 if TYPE_CHECKING:
     from _typeshed import StrOrBytesPath, StrPath
 
-MYPY_PROTOBUF_VERSION = mypy_protobuf__version__
+MYPY_PROTOBUF_VERSION = _mypy_protobuf_version
 
 
 def download_file(url: str, destination: Path) -> None:

diff --git a/stdlib/@tests/stubtest_allowlists/common.txt b/stdlib/@tests/stubtest_allowlists/common.txt
@@ -6,9 +6,6 @@
 
 importlib.abc.MetaPathFinder.find_spec  # Not defined on the actual class, but expected to exist.
 importlib.abc.PathEntryFinder.find_spec  # Not defined on the actual class, but expected to exist.
-tkinter.simpledialog.[A-Z_]+
-tkinter.simpledialog.TclVersion
-tkinter.simpledialog.TkVersion
 tarfile.TarInfo.__slots__  # it's a big dictionary at runtime and the dictionary values are a bit long
 
 
@@ -457,17 +454,6 @@ typing(_extensions)?\.TextIO\.newlines
 typing(_extensions)?\.IO\.__iter__
 typing(_extensions)?\.IO\.__next__
 
-# typing.IO uses positional-or-keyword arguments, but in the stubs we prefer
-# to mark these as positional-only for compatibility with existing sub-classes.
-typing(_extensions)?\.BinaryIO\.write
-typing(_extensions)?\.IO\.read
-typing(_extensions)?\.IO\.readline
-typing(_extensions)?\.IO\.readlines
-typing(_extensions)?\.IO\.seek
-typing(_extensions)?\.IO\.truncate
-typing(_extensions)?\.IO\.write
-typing(_extensions)?\.IO\.writelines
-
 types.MethodType.__closure__  # read-only but not actually a property; stubtest thinks it doesn't exist.
 types.MethodType.__code__  # read-only but not actually a property; stubtest thinks it doesn't exist.
 types.MethodType.__defaults__  # read-only but not actually a property; stubtest thinks it doesn't exist.
@@ -499,7 +485,3 @@ xml.etree.ElementTree.XMLParser.__init__  # Defined in C so has general signatur
 # Iterable classes that don't define __iter__ at runtime (usually iterable via __getitem__)
 # These would ideally be special-cased by type checkers; see https://github.com/python/mypy/issues/2220
 xml.etree.ElementTree.Element.__iter__
-
-# These three have a pos-or-keyword first parameter at runtime, but deliberately have a pos-only first parameter in the stub. #6812
-posixpath.join
-ntpath.join
diff --git a/stdlib/@tests/stubtest_allowlists/darwin-py315.txt b/stdlib/@tests/stubtest_allowlists/darwin-py315.txt
@@ -0,0 +1,25 @@
+_decimal.SPEC_VERSION
+_pyrepl.fancy_termios
+_pyrepl.unix_console
+_pyrepl.unix_eventqueue
+ctypes.c_double_complex._type_
+ctypes.c_float_complex._type_
+ctypes.c_longdouble_complex._type_
+decimal.SPEC_VERSION
+mmap.MS_ASYNC
+mmap.MS_INVALIDATE
+mmap.MS_SYNC
+mmap.mmap.madvise
+mmap.mmap.resize
+os.NODEV
+os.__all__
+posix.NODEV
+profiling.sampling.live_collector
+profiling.sampling.live_collector.collector
+profiling.sampling.live_collector.constants
+profiling.sampling.live_collector.display
+profiling.sampling.live_collector.trend_tracker
+profiling.sampling.live_collector.widgets
+readline.get_pre_input_hook
+resource.RLIM_SAVED_CUR
+resource.RLIM_SAVED_MAX
diff --git a/stdlib/@tests/stubtest_allowlists/linux-py315.txt b/stdlib/@tests/stubtest_allowlists/linux-py315.txt
@@ -0,0 +1,129 @@
+_decimal
+_pyrepl.fancy_termios
+_pyrepl.unix_console
+_pyrepl.unix_eventqueue
+_socket.CAN_ISOTP_CHK_PAD_DATA
+_socket.CAN_ISOTP_CHK_PAD_LEN
+_socket.CAN_ISOTP_DEFAULT_EXT_ADDRESS
+_socket.CAN_ISOTP_DEFAULT_FLAGS
+_socket.CAN_ISOTP_DEFAULT_FRAME_TXTIME
+_socket.CAN_ISOTP_DEFAULT_LL_MTU
+_socket.CAN_ISOTP_DEFAULT_LL_TX_DL
+_socket.CAN_ISOTP_DEFAULT_LL_TX_FLAGS
+_socket.CAN_ISOTP_DEFAULT_PAD_CONTENT
+_socket.CAN_ISOTP_DEFAULT_RECV_BS
+_socket.CAN_ISOTP_DEFAULT_RECV_STMIN
+_socket.CAN_ISOTP_DEFAULT_RECV_WFTMAX
+_socket.CAN_ISOTP_EXTEND_ADDR
+_socket.CAN_ISOTP_FORCE_RXSTMIN
+_socket.CAN_ISOTP_FORCE_TXSTMIN
+_socket.CAN_ISOTP_HALF_DUPLEX
+_socket.CAN_ISOTP_LISTEN_MODE
+_socket.CAN_ISOTP_LL_OPTS
+_socket.CAN_ISOTP_OPTS
+_socket.CAN_ISOTP_RECV_FC
+_socket.CAN_ISOTP_RX_EXT_ADDR
+_socket.CAN_ISOTP_RX_PADDING
+_socket.CAN_ISOTP_RX_STMIN
+_socket.CAN_ISOTP_SF_BROADCAST
+_socket.CAN_ISOTP_TX_PADDING
+_socket.CAN_ISOTP_TX_STMIN
+_socket.CAN_ISOTP_WAIT_TX_DONE
+_socket.IPV6_HDRINCL
+_socket.SOL_CAN_ISOTP
+ctypes.c_double_complex._type_
+ctypes.c_float_complex._type_
+ctypes.c_longdouble_complex._type_
+# GitHub Actions' Python 3.15 Linux build currently lacks _decimal, so
+# decimal falls back to _pydecimal with different runtime signatures.
+decimal\..*
+mmap.MS_ASYNC
+mmap.MS_INVALIDATE
+mmap.MS_SYNC
+mmap.mmap.madvise
+os.AT_NO_AUTOMOUNT
+os.AT_STATX_DONT_SYNC
+os.AT_STATX_FORCE_SYNC
+os.AT_STATX_SYNC_AS_STAT
+os.NODEV
+os.STATX_ATIME
+os.STATX_BASIC_STATS
+os.STATX_BLOCKS
+os.STATX_BTIME
+os.STATX_CTIME
+os.STATX_DIOALIGN
+os.STATX_GID
+os.STATX_INO
+os.STATX_MNT_ID
+os.STATX_MNT_ID_UNIQUE
+os.STATX_MODE
+os.STATX_MTIME
+os.STATX_NLINK
+os.STATX_SIZE
+os.STATX_TYPE
+os.STATX_UID
+os.__all__
+os._clearenv
+os.statx
+os.statx_result
+posix.AT_NO_AUTOMOUNT
+posix.AT_STATX_DONT_SYNC
+posix.AT_STATX_FORCE_SYNC
+posix.AT_STATX_SYNC_AS_STAT
+posix.NODEV
+posix.STATX_ATIME
+posix.STATX_BASIC_STATS
+posix.STATX_BLOCKS
+posix.STATX_BTIME
+posix.STATX_CTIME
+posix.STATX_DIOALIGN
+posix.STATX_GID
+posix.STATX_INO
+posix.STATX_MNT_ID
+posix.STATX_MNT_ID_UNIQUE
+posix.STATX_MODE
+posix.STATX_MTIME
+posix.STATX_NLINK
+posix.STATX_SIZE
+posix.STATX_TYPE
+posix.STATX_UID
+posix.statx
+profiling.sampling.live_collector
+profiling.sampling.live_collector.collector
+profiling.sampling.live_collector.constants
+profiling.sampling.live_collector.display
+profiling.sampling.live_collector.trend_tracker
+profiling.sampling.live_collector.widgets
+readline.get_pre_input_hook
+resource.RLIM_SAVED_CUR
+resource.RLIM_SAVED_MAX
+socket.CAN_ISOTP_CHK_PAD_DATA
+socket.CAN_ISOTP_CHK_PAD_LEN
+socket.CAN_ISOTP_DEFAULT_EXT_ADDRESS
+socket.CAN_ISOTP_DEFAULT_FLAGS
+socket.CAN_ISOTP_DEFAULT_FRAME_TXTIME
+socket.CAN_ISOTP_DEFAULT_LL_MTU
+socket.CAN_ISOTP_DEFAULT_LL_TX_DL
+socket.CAN_ISOTP_DEFAULT_LL_TX_FLAGS
+socket.CAN_ISOTP_DEFAULT_PAD_CONTENT
+socket.CAN_ISOTP_DEFAULT_RECV_BS
+socket.CAN_ISOTP_DEFAULT_RECV_STMIN
+socket.CAN_ISOTP_DEFAULT_RECV_WFTMAX
+socket.CAN_ISOTP_EXTEND_ADDR
+socket.CAN_ISOTP_FORCE_RXSTMIN
+socket.CAN_ISOTP_FORCE_TXSTMIN
+socket.CAN_ISOTP_HALF_DUPLEX
+socket.CAN_ISOTP_LISTEN_MODE
+socket.CAN_ISOTP_LL_OPTS
+socket.CAN_ISOTP_OPTS
+socket.CAN_ISOTP_RECV_FC
+socket.CAN_ISOTP_RX_EXT_ADDR
+socket.CAN_ISOTP_RX_PADDING
+socket.CAN_ISOTP_RX_STMIN
+socket.CAN_ISOTP_SF_BROADCAST
+socket.CAN_ISOTP_TX_PADDING
+socket.CAN_ISOTP_TX_STMIN
+socket.CAN_ISOTP_WAIT_TX_DONE
+socket.IPV6_HDRINCL
+socket.SOL_CAN_ISOTP
+socket.__all__
diff --git a/stdlib/@tests/stubtest_allowlists/py310.txt b/stdlib/@tests/stubtest_allowlists/py310.txt
@@ -2,7 +2,6 @@
 # New errors in Python 3.10
 # =========================
 
-
 # =========
 # 3.10 only
 # =========
@@ -134,6 +133,35 @@ importlib.abc.Traversable.open  # Problematic protocol signature at runtime, see
 typing_extensions.TypeAliasType.__call__
 
 
+# =====
+# <3.15
+# =====
+
+tkinter.simpledialog.[A-Z_]+
+tkinter.simpledialog.TclVersion
+tkinter.simpledialog.TkVersion
+
+
+# =============================================================
+# Allowlist entries that cannot or should not be fixed; <3.15
+# =============================================================
+
+# typing.IO uses positional-or-keyword arguments, but in the stubs we prefer
+# to mark these as positional-only for compatibility with existing sub-classes.
+typing(_extensions)?\.BinaryIO\.write
+typing(_extensions)?\.IO\.read
+typing(_extensions)?\.IO\.readline
+typing(_extensions)?\.IO\.readlines
+typing(_extensions)?\.IO\.seek
+typing(_extensions)?\.IO\.truncate
+typing(_extensions)?\.IO\.write
+typing(_extensions)?\.IO\.writelines
+
+# These have a pos-or-keyword first parameter at runtime, but deliberately have a pos-only first parameter in the stub. #6812
+posixpath.join
+ntpath.join
+
+
 # ===============================================================
 # Allowlist entries that cannot or should not be fixed; 3.10 only
 # ===============================================================

diff --git a/stdlib/@tests/stubtest_allowlists/py311.txt b/stdlib/@tests/stubtest_allowlists/py311.txt
@@ -2,7 +2,6 @@
 # New errors in Python 3.11
 # =========================
 
-
 # =======
 # >= 3.11
 # =======
@@ -108,6 +107,35 @@ typing_extensions.TypeAliasType.__call__
 enum.Enum.__init__
 
 
+# =====
+# <3.15
+# =====
+
+tkinter.simpledialog.[A-Z_]+
+tkinter.simpledialog.TclVersion
+tkinter.simpledialog.TkVersion
+
+
+# =============================================================
+# Allowlist entries that cannot or should not be fixed; <3.15
+# =============================================================
+
+# typing.IO uses positional-or-keyword arguments, but in the stubs we prefer
+# to mark these as positional-only for compatibility with existing sub-classes.
+typing(_extensions)?\.BinaryIO\.write
+typing(_extensions)?\.IO\.read
+typing(_extensions)?\.IO\.readline
+typing(_extensions)?\.IO\.readlines
+typing(_extensions)?\.IO\.seek
+typing(_extensions)?\.IO\.truncate
+typing(_extensions)?\.IO\.write
+typing(_extensions)?\.IO\.writelines
+
+# These have a pos-or-keyword first parameter at runtime, but deliberately have a pos-only first parameter in the stub. #6812
+posixpath.join
+ntpath.join
+
+
 # =============================================================
 # Allowlist entries that cannot or should not be fixed; >= 3.11
 # =============================================================