See http://buildbot.python.org/all/builders/PPC64%20PowerLinux%202.7/builds/396/steps/test/logs/stdio.

======================================================================
ERROR: test_getsetlocale_issue1813 (test.test_locale.TestMiscellaneous)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/shager/cpython-buildarea/2.7.edelsohn-powerlinux-ppc64/build/Lib/test/test_locale.py", line 480, in test_getsetlocale_issue1813
    locale.setlocale(locale.LC_CTYPE, loc)
  File "/home/shager/cpython-buildarea/2.7.edelsohn-powerlinux-ppc64/build/Lib/locale.py", line 579, in setlocale
    return _setlocale(category, locale)
Error: unsupported locale setting

----------------------------------------------------------------------

I don't know why this fails exactly. I had a similar failure though that was fixed by using the @run_with_locale decorator.

New changeset 3696b9ae6b17 by Serhiy Storchaka in branch '2.7':
Issue #20086: Output more details when test_getsetlocale_issue1813 is failed.
http://hg.python.org/cpython/rev/3696b9ae6b17

Detailed output:
http://buildbot.python.org/all/builders/PPC64%20PowerLinux%202.7/builds/415/steps/test/logs/stdio
======================================================================
FAIL: test_getsetlocale_issue1813 (test.test_locale.TestMiscellaneous)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/shager/cpython-buildarea/2.7.edelsohn-powerlinux-ppc64/build/Lib/test/test_locale.py", line 484, in test_getsetlocale_issue1813
    (loc, oldlocale, e))
AssertionError: Failed to set locale ('tr_TR', 'ISO8859-9') (default locale is (None, None)): Error('unsupported locale setting',)

----------------------------------------------------------------------

locale.getlocale() calls _parse_localename() which uses normalize() which maps 'tr_TR' to 'tr_TR.ISO8859-9' with according to locale_alias table. However on this platform tr_TR.ISO8859-9 doesn't not exist, only tr_TR.

This bug is occured not only on PPC64 PowerLinux. See also:

http://buildbot.python.org/all/builders/x86%20RHEL%206%202.7/builds/975/steps/test/logs/stdio
http://buildbot.python.org/all/builders/AMD64%20Fedora%20without%20threads%202.7/builds/1644/steps/test/logs/stdio

3d805bee06e2 uses str.lower(), which fails on the Turkish 'i' if the Turkish locale is set:


Python 2.7.6+ (2.7:0e5df5b62488+, Jan 10 2014, 23:25:35) 
[GCC 4.6.3 20120306 (Red Hat 4.6.3-2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import locale
>>> locale.setlocale(locale.LC_CTYPE, ('tr_TR', 'ISO8859-9'))
'tr_TR.ISO8859-9'
>>> 'tr_TR.ISO8859-9'.lower()
'tr_tr.\xfdso8859-9'

I'm not sure if str.lower() is supposed to use tolower() in
stringobject.c. If tolower() is replaced by Py_TOLOWER(), the
problem disappears.

But maybe the locale dependent tolower() is used on purpose.

Ignore me, the fine manual says that "For 8-bit strings, this method is
locale-dependent."

Good catch, Stefan!

Here is a patch which restores old behavior. It also changes test_locale to try several Turkish locale names. On some platforms (as Ubuntu) bare tr_TR is not exist, but only tr_TK.utf8. This will increase chance for this test to run.

New changeset bac50f54d357 by Serhiy Storchaka in branch '2.7':
Issue #20086: Restored the use of locale-independing mapping instead of
http://hg.python.org/cpython/rev/bac50f54d357