$ LC_ALL=uk_UA.koi8u ./python -m testTraceback (most recent call last):  File "<frozen runpy>", line 198, in _run_module_as_main  File "<frozen runpy>", line 88, in _run_code  File "/home/serhiy/py/cpython/Lib/test/__main__.py", line 2, in <module>    main()    ^^^^^^  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 737, in main    Regrtest().main(tests=tests, **kwargs)    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/contextlib.py", line 155, in __exit__    self.gen.throw(typ, value, traceback)    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/contextlib.py", line 155, in __exit__    self.gen.throw(typ, value, traceback)    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/test/support/os_helper.py", line 396, in temp_dir    yield path    ^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/contextlib.py", line 155, in __exit__    self.gen.throw(typ, value, traceback)    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/test/support/os_helper.py", line 427, in change_cwd    yield os.getcwd()    ^^^^^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/test/support/os_helper.py", line 449, in temp_cwd    yield cwd_dir    ^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 675, in main    self._main(tests, kwargs)    ^^^^^^^^^^^^^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 704, in _main    setup_tests(self.ns)    ^^^^^^^^^^^^^^^^^^^^  File "/home/serhiy/py/cpython/Lib/test/libregrtest/setup.py", line 107, in setup_tests    os.environ.setdefault(    ^^^^^^^^^^^^^^^^^^^^^^  File "<frozen os>", line 717, in setdefault  File "<frozen os>", line 683, in __setitem__  File "<frozen os>", line 758, in encode  File "/home/serhiy/py/cpython/Lib/encodings/koi8_u.py", line 12, in encode    return codecs.charmap_encode(input,errors,encoding_table)           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^UnicodeEncodeError: 'charmap' codec can't encode character '\U0001f60e' in position 0: character maps to <undefined>