Title: Mac OS X locale setup in thread happens sometime after run() is called
Type: behavior Stage: resolved
Components: macOS Versions: Python 3.4
Status: closed Resolution: works for me
Dependencies: Superseder:
Assigned To: Nosy List: barry-scott, ned.deily, r.david.murray, ronaldoussoren
Priority: normal Keywords:

Created on 2015-03-28 10:47 by barry-scott, last changed 2020-10-23 19:34 by ronaldoussoren. This issue is now closed.

File name Uploaded Description Edit barry-scott, 2015-03-29 11:00
Messages (6)
msg239458 - (view) Author: Barry Alan Scott (barry-scott) * Date: 2015-03-28 10:47
I'm seeing a random traceback when starting a new thread on Mac OS X 10.10.2 with python 3.4.3 final.

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/", line 920, in _bootstrap_inner
  File "/Users/barry/wc/svn/pysvn-phoenix/WorkBench/Source/", line 40, in run 'BackgroundThread locale %r' % (locale.getlocale(),) )
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/", line 575, in getlocale
    return _parse_localename(localename)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/", line 484, in _parse_localename
    raise ValueError('unknown locale: %s' % localename)
ValueError: unknown locale: UTF-8

Adding a time.sleep( 5 ) prevents the traceback.

Using _locale.setlocale( locale.LC_ALL, None ) to see the state with interfering it looks like the locale is being initialised in the thread after run() is called. (Make no sense to me, but I can reproduce).

I have failed to create a small script to show this bug.
msg239461 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-03-28 17:10
This is probably related to or effectively a duplicate of issue 18378, which looks to be an Apple bug.

Do you have the problem if you remove the getlocale() call?
msg239464 - (view) Author: Ned Deily (ned.deily) * (Python committer) Date: 2015-03-28 19:57
The behavior noted in Issue18378 isn't an Apple bug; it's a GNU vs BSD difference.  Can you avoid the problem by calling locale.getlocale() in the main program before creating any threads?
msg239484 - (view) Author: Barry Alan Scott (barry-scott) * Date: 2015-03-29 11:00
I should point out using Python2.7 with wxPython I do not see this issue.
This issue was exposed during my efforts to port pysvn from py2.7+wxPython to py3.4+wxpython-phoenix.

I do setup locale on the main thread very early before starting the background thread.
I have attached the initLocale() I use.

The background thread needs the locale setup and I use getlocale() to prove that it is setup.

I do not see this as a duplicate of Issue18378 as I can init the locale. 

The problem, and I could believe its an OSX bug, is that new threads do not return the expected locale from _locale.setlocale() for a period of time, approx 2s after starting up.
msg379467 - (view) Author: Ronald Oussoren (ronaldoussoren) * (Python committer) Date: 2020-10-23 19:33
I've been using the scriptlet below to try to attempt to reproduce the problem. I'm not sure if this matches the way the program of the OP is set up.

The scriptlet below works for me without problems (macOS 10.15, Python 3.4 - 3.9).

This either means the problem has been fixed in the meantime (if it was an OS bug), or my script doesn't reproduce the problematic setup.

The traceback in the first message is due to LC_CTYPE=UTF-8 in the default shell environment on macOS, which wasn't recognised by for a long time. That issue has been fixed though.

# ----
import locale
import threading

def thread():
    print("thread locale:", locale.getlocale())

locale.setlocale(locale.LC_ALL, "en_US.UTF-8")

t = threading.Thread(target=thread)
msg379468 - (view) Author: Ronald Oussoren (ronaldoussoren) * (Python committer) Date: 2020-10-23 19:34
I'm closing this issue as "works for me". Please re-open if there is more information on how to reproduce the problem.
Date User Action Args
2020-10-23 19:34:57ronaldoussorensetstatus: open -> closed
type: behavior
messages: + msg379468

resolution: works for me
stage: resolved
2020-10-23 19:33:57ronaldoussorensetmessages: + msg379467
2015-03-29 11:00:56barry-scottsetfiles: +

messages: + msg239484
2015-03-28 19:57:11ned.deilysetmessages: + msg239464
2015-03-28 17:10:28r.david.murraysetnosy: + ronaldoussoren, r.david.murray, ned.deily
messages: + msg239461
components: + macOS
2015-03-28 10:47:55barry-scottcreate