From c2e0db42774129cbdce42d1a9ecbee4d38292d7b Mon Sep 17 00:00:00 2001
From: Ned Deily <nad@python.org>
Date: Wed, 5 Aug 2026 02:41:49 -0400
Subject: [PATCH 1/2] gh-153711: Avoid use of dup3 and pipe2 calls introduced
 in macOS 27

This prevents potential segfaults when builds are used on older
systems and avoids adding new code for supporting weaklinking.
---
 ...-08-05-02-02-33.gh-issue-153711.pO9fFb.rst |  3 ++
 configure                                     | 32 +++++++++++--------
 configure.ac                                  |  8 ++++-
 3 files changed, 29 insertions(+), 14 deletions(-)
 create mode 100644 Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst

diff --git a/Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst b/Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst
new file mode 100644
index 00000000000000..61b9db996a7935
--- /dev/null
+++ b/Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst
@@ -0,0 +1,3 @@
++On macOS, do not attempt to use the :manpage:`dup3(2)` and
++:manpage:`pipe2(2)` system calls introduced in
+macOS 27 to prevent problems when running on older systems.
diff --git a/configure b/configure
index c42bffecdcfcdd..51e657ff0d61e3 100755
--- a/configure
+++ b/configure
@@ -19381,13 +19381,7 @@ fi
 # header definition prevents usage - autoconf doesn't use the headers), or
 # raise an error if used at runtime. Force these symbols off.
 if test "$ac_sys_system" != "iOS" ; then
-  ac_fn_c_check_func "$LINENO" "dup3" "ac_cv_func_dup3"
-if test "x$ac_cv_func_dup3" = xyes
-then :
-  printf "%s\n" "#define HAVE_DUP3 1" >>confdefs.h
-
-fi
-ac_fn_c_check_func "$LINENO" "getentropy" "ac_cv_func_getentropy"
+  ac_fn_c_check_func "$LINENO" "getentropy" "ac_cv_func_getentropy"
 if test "x$ac_cv_func_getentropy" = xyes
 then :
   printf "%s\n" "#define HAVE_GETENTROPY 1" >>confdefs.h
@@ -19398,12 +19392,6 @@ if test "x$ac_cv_func_getgroups" = xyes
 then :
   printf "%s\n" "#define HAVE_GETGROUPS 1" >>confdefs.h
 
-fi
-ac_fn_c_check_func "$LINENO" "pipe2" "ac_cv_func_pipe2"
-if test "x$ac_cv_func_pipe2" = xyes
-then :
-  printf "%s\n" "#define HAVE_PIPE2 1" >>confdefs.h
-
 fi
 ac_fn_c_check_func "$LINENO" "system" "ac_cv_func_system"
 if test "x$ac_cv_func_system" = xyes
@@ -19412,6 +19400,24 @@ then :
 
 fi
 
+fi
+# In addition, macOS introduced dup3 and pipe2 in macOS 27, late in the
+# lifetime of this version of Python. Rather than adding weaklinking
+# support for them, just continue to ignore them.
+if test "$ac_sys_system" != "iOS" -a "$ac_sys_system" != "Darwin"; then
+  ac_fn_c_check_func "$LINENO" "dup3" "ac_cv_func_dup3"
+if test "x$ac_cv_func_dup3" = xyes
+then :
+  printf "%s\n" "#define HAVE_DUP3 1" >>confdefs.h
+
+fi
+ac_fn_c_check_func "$LINENO" "pipe2" "ac_cv_func_pipe2"
+if test "x$ac_cv_func_pipe2" = xyes
+then :
+  printf "%s\n" "#define HAVE_PIPE2 1" >>confdefs.h
+
+fi
+
 fi
 
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC options needed to detect all undeclared functions" >&5
diff --git a/configure.ac b/configure.ac
index 047005fd7177b6..f93a9f29b39aff 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5282,7 +5282,13 @@ fi
 # header definition prevents usage - autoconf doesn't use the headers), or
 # raise an error if used at runtime. Force these symbols off.
 if test "$ac_sys_system" != "iOS" ; then
-  AC_CHECK_FUNCS([dup3 getentropy getgroups pipe2 system])
+  AC_CHECK_FUNCS([getentropy getgroups system])
+fi
+# In addition, macOS introduced dup3 and pipe2 in macOS 27, late in the
+# lifetime of this version of Python. Rather than adding weaklinking
+# support for them, just continue to ignore them.
+if test "$ac_sys_system" != "iOS" -a "$ac_sys_system" != "Darwin"; then
+  AC_CHECK_FUNCS([dup3 pipe2])
 fi
 
 AC_CHECK_DECL([dirfd],

From 5ab616404762eea28f124d51cca4b3b19be1571e Mon Sep 17 00:00:00 2001
From: Ned Deily <nad@python.org>
Date: Wed, 5 Aug 2026 02:56:48 -0400
Subject: [PATCH 2/2] Fix hasty typos

---
 .../next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst b/Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst
index 61b9db996a7935..90804c179a4b4a 100644
--- a/Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst
+++ b/Misc/NEWS.d/next/macOS/2026-08-05-02-02-33.gh-issue-153711.pO9fFb.rst
@@ -1,3 +1,3 @@
-+On macOS, do not attempt to use the :manpage:`dup3(2)` and
-+:manpage:`pipe2(2)` system calls introduced in
+On macOS, do not attempt to use the :manpage:`dup3(2)` and
+:manpage:`pipe2(2)` system calls introduced in
 macOS 27 to prevent problems when running on older systems.