[Python-checkins] [docs] Update documentation for `multiprocessing.get_start_method` (GH-18170) (GH-28534)

[ambv]

https://github.com/python/cpython/commit/b97f1f82a313918dfdddec8b3492728c8dfae255
commit: b97f1f82a313918dfdddec8b3492728c8dfae255
branch: 3.9
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: ambv <lukasz at langa.pl>
date: 2021-09-23T23:39:08+02:00
summary:

[docs] Update documentation for `multiprocessing.get_start_method` (GH-18170) (GH-28534)

(cherry picked from commit af90b5498b8c6acd67b50fdad007d26dfd1c5823)

Co-authored-by: Sam Sneddon <me at gsnedders.com>

files:
M Doc/library/multiprocessing.rst

diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index 57a07dc1070e1..7588e1ddb80a6 100644
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -1030,7 +1030,13 @@ Miscellaneous
 
    The return value can be ``'fork'``, ``'spawn'``, ``'forkserver'``
    or ``None``.  ``'fork'`` is the default on Unix, while ``'spawn'`` is
-   the default on Windows.
+   the default on Windows and macOS.
+
+.. versionchanged:: 3.8
+
+   On macOS, the *spawn* start method is now the default.  The *fork* start
+   method should be considered unsafe as it can lead to crashes of the
+   subprocess. See :issue:`33725`.
 
    .. versionadded:: 3.4