bpo-37951: Lift subprocess's fork() restriction (GH-15544)
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 7e1e3f9..167ed9a 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -483,6 +483,13 @@
The *start_new_session* parameter can take the place of a previously
common use of *preexec_fn* to call os.setsid() in the child.
+ .. versionchanged:: 3.8
+
+ The *preexec_fn* parameter is no longer supported in subinterpreters.
+ The use of the parameter in a subinterpreter raises
+ :exc:`RuntimeError`. The new restriction may affect applications that
+ are deployed in mod_wsgi, uWSGI, and other embedded environments.
+
If *close_fds* is true, all file descriptors except :const:`0`, :const:`1` and
:const:`2` will be closed before the child process is executed. Otherwise
when *close_fds* is false, file descriptors obey their inheritable flag