Unpin Python 3.13 and 3.14 (#15634)

stdlib/@tests/stubtest_allowlists/darwin-py313.txt

@@ -1,3 +1,13 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.13.13, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp
+
 # =======
 # >= 3.13
 # =======

stdlib/@tests/stubtest_allowlists/darwin-py314.txt

@@ -1,3 +1,13 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.14.4, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp
+
 # =========
 # 3.14 only
 # =========

stdlib/@tests/stubtest_allowlists/linux-py313.txt

@@ -0,0 +1,9 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.13.13, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp

stdlib/@tests/stubtest_allowlists/linux-py314.txt

@@ -1,3 +1,13 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.14.4, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp
+
 # =========
 # 3.14 only
 # =========

stdlib/os/__init__.pyi

@@ -1532,7 +1532,36 @@ else:
     def WSTOPSIG(status: int) -> int: ...
     def WTERMSIG(status: int) -> int: ...
 
-    if sys.version_info >= (3, 13):
+    if sys.version_info >= (3, 15):
+        def posix_spawn(
+            path: StrOrBytesPath,
+            argv: _ExecVArgs,
+            env: _ExecEnv | None,
+            /,
+            *,
+            file_actions: Sequence[tuple[Any, ...]] | None = (),
+            setpgroup: int | None = None,  # None allowed starting in 3.15
+            resetids: bool = False,
+            setsid: bool = False,
+            setsigmask: Iterable[int] = (),
+            setsigdef: Iterable[int] = (),
+            scheduler: tuple[Any, sched_param] | None = None,  # None allowed starting in 3.15
+        ) -> int: ...
+        def posix_spawnp(
+            path: StrOrBytesPath,
+            argv: _ExecVArgs,
+            env: _ExecEnv | None,
+            /,
+            *,
+            file_actions: Sequence[tuple[Any, ...]] | None = (),
+            setpgroup: int | None = None,  # None allowed starting in 3.15
+            resetids: bool = False,
+            setsid: bool = False,
+            setsigmask: Iterable[int] = (),
+            setsigdef: Iterable[int] = (),
+            scheduler: tuple[Any, sched_param] | None = None,  # None allowed starting in 3.15
+        ) -> int: ...
+    elif sys.version_info >= (3, 13):
         def posix_spawn(
             path: StrOrBytesPath,
             argv: _ExecVArgs,