[New-bugs-announce] [issue39244] multiprocessing.get_all_start_methods() wrong default on macOS

[Stefan Holek]

New submission from Stefan Holek <stefan at epy.co.at>:

In Python 3.8 the default start method has changed from fork to spawn on macOS.
https://docs.python.org/3/whatsnew/3.8.html#multiprocessing

get_all_start_methods() says: "Returns a list of the supported start methods, the first of which is the default."
https://docs.python.org/3/library/multiprocessing.html?highlight=finalize#multiprocessing.get_all_start_methods

However, it appears to still return fork as default:

  Python 3.8.1 (default, Dec 22 2019, 03:45:23) 
  [Clang 10.0.1 (clang-1001.0.46.4)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  >>> import multiprocessing
  >>> multiprocessing.get_all_start_methods()
  ['fork', 'spawn', 'forkserver']
  >>> 

Thank you!

----------
components: Library (Lib), macOS
messages: 359503
nosy: ned.deily, ronaldoussoren, stefanholek
priority: normal
severity: normal
status: open
title: multiprocessing.get_all_start_methods() wrong default on macOS
type: behavior
versions: Python 3.8

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue39244>
_______________________________________