test_re fails on Alpine Linux (with musl)

[prashanthallu]

Bug report

Bug description:

718.6 0:01:10 load avg: 0.97 [35/44] test_re
719.7 test test_re failed
719.7 0:01:11 load avg: 0.98 [36/44] test_set -- test_re failed (2 failures)
724.7 0:01:16 load avg: 0.98 [37/44] test_sqlite3
725.6 0:01:17 load avg: 0.98 [38/44] test_statistics
733.0 0:01:24 load avg: 0.98 [39/44] test_str
735.1 0:01:26 load avg: 0.98 [40/44] test_struct
735.8 0:01:27 load avg: 0.98 [41/44] test_tabnanny
736.3 0:01:28 load avg: 0.98 [42/44] test_time
739.5 0:01:31 load avg: 0.98 [43/44] test_xml_etree
740.2 0:01:32 load avg: 0.98 [44/44] test_xml_etree_c
741.3
741.3 Total duration: 1 min 33 sec
741.3 Total tests: run=9,178 failures=3 skipped=203
741.3 Total test files: run=44/44 failed=2 skipped=2
741.3 Result: FAILURE
741.3 make: *** [Makefile:886: profile-run-stamp] Error 2

And while running in verbose mode the following is the output of it.



 ./python -m unittest -v test.test_re
(...)
======================================================================
FAIL: test_locale_caching (test.test_re.ReTests.test_locale_caching)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Python-3.13.2/Lib/test/test_re.py", line 2195, in test_locale_caching
    self.check_en_US_iso88591()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Python-3.13.2/Lib/test/test_re.py", line 2204, in check_en_US_iso88591
    self.assertTrue(re.match(b'\xc5', b'\xe5', re.L|re.I))
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: None is not true

======================================================================
FAIL: test_locale_compiled (test.test_re.ReTests.test_locale_compiled)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Python-3.13.2/Lib/test/test_re.py", line 2240, in test_locale_compiled
    self.assertTrue(p.match(b'\xe5\xe5'))
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: None is not true

----------------------------------------------------------------------
Ran 165 tests in 0.838s

FAILED (failures=2, skipped=1)

CPython versions tested on:

3.13

Operating systems tested on:

Linux

[StanFromIreland]

Do you have en_US_iso88591 installed? Check with:

locale -a | grep en_US

Both of the tests depend on it.

I presume it is setting a locale that is not available for some reason.

        for loc in 'en_US.iso88591', 'en_US.utf8':
            try:
                locale.setlocale(locale.LC_CTYPE, loc)
            except locale.Error:
                # Unsupported locale on this system
                self.skipTest('test needs %s locale' % loc)

I am unable to reproduce after deleting locale:

test_locale_caching (test.test_re.ReTests.test_locale_caching) ... skipped 'test needs en_US.iso88591 locale'
test_locale_compiled (test.test_re.ReTests.test_locale_compiled) ... skipped 'test needs en_US.iso88591 locale'

[vstinner]

@StanFromIreland: Do you link Python to the musl C library?

[StanFromIreland]

@vstinner: I should have specified, I did not. I am not sure whether it is even packaged for Fedora.

[vstinner]

musl is package in Fedora, but I failed to build Python using musl-gcc wrapper. I built Python in Alpine to get musl.

[serhiy-storchaka]

Please add the following lines at the beginning of test_locale_compiled() and show the output.

        print()
        print(f'LC_CTYPE: {locale.setlocale(locale.LC_CTYPE)}')
        print(f'LC_COLLATE: {locale.setlocale(locale.LC_COLLATE)}')
        print(f'LC_ALL: {locale.setlocale(locale.LC_ALL)}')

[vstinner]

Please add the following lines at the beginning of test_locale_compiled() and show the output.

Here you have:

test_locale_compiled (test.test_re.ReTests.test_locale_compiled) ... 
LC_CTYPE: C.UTF-8
LC_COLLATE: C
LC_ALL: C.UTF-8;C;C;C;C;C
FAIL

[vstinner]

Using musl, setlocale() doesn't fail even if the locale isn't supported:

$ ./python 
Python 3.14.0a5+ (heads/main-dirty:fe186d76cfd, Mar 11 2025, 08:54:51) [GCC 14.2.0] on linux
>>> import locale
>>> locale.setlocale(locale.LC_CTYPE, 'en_US.iso88591')
'en_US.iso88591'
>>> locale.getencoding()
'UTF-8'

Another example:

>>> import locale
>>> locale.setlocale(locale.LC_CTYPE, 'donotexist')
'donotexist'
>>> locale.getencoding()
'UTF-8'

[vstinner]

See also #131313