gh-154227: Fix os.posix_openpt() on OpenBSD (GH-154228)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

diff --git a/Misc/NEWS.d/next/Library/2026-07-20-14-00-00.gh-issue-154227.openpt.rst b/Misc/NEWS.d/next/Library/2026-07-20-14-00-00.gh-issue-154227.openpt.rst
new file mode 100644 (file)
index 0000000..e33d090
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-07-20-14-00-00.gh-issue-154227.openpt.rst
@@ -0,0 +1,2 @@
+Fix :func:`os.posix_openpt` on OpenBSD, where it rejected the
+:data:`~os.O_CLOEXEC` flag.

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 02d25adddd6267578f4b6718dec64bd4bbe6cfc5..69f01e04244d5bd028afda11a56e6f6d6794a6e5 100644 (file)
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -9186,7 +9186,9 @@ os_posix_openpt_impl(PyObject *module, int oflag)
 {
     int fd;
 
-#if defined(O_CLOEXEC)
+    // OpenBSD posix_openpt() rejects any flag other than O_RDWR and
+    // O_NOCTTY; the fd is made non-inheritable below in any case.
+#if defined(O_CLOEXEC) && !defined(__OpenBSD__)
     oflag |= O_CLOEXEC;
 #endif