The test was originally run with

% echo $LANG
tcsh: LANG: Undefined variable.

The same failure occurs with LANG set to C 

% env LANG=C ../Python-3.0rc3/python.exe Lib/test/test_cmd_line.py
test_directories (__main__.CmdLineTest) ... ok
....
FAILED (failures=1)
Traceback (most recent call last):
  File "Lib/test/test_cmd_line.py", line 151, in <module>
    test_main()
  File "Lib/test/test_cmd_line.py", line 147, in test_main
    test.support.run_unittest(CmdLineTest)
  File "/Users/jean/Desktop/Python-3.0rc3/Lib/test/support.py", line 
698, in run_unittest
    _run_suite(suite)
  File "/Users/jean/Desktop/Python-3.0rc3/Lib/test/support.py", line 
681, in _run_suite
    raise TestFailed(err)
test.support.TestFailed: Traceback (most recent call last):
  File "Lib/test/test_cmd_line.py", line 143, in test_run_code
    0)
AssertionError: 1 != 0


But the test passes in both these cases:

% env LANG=en_US.UTF-8 ../Python-3.0rc3/python.exe 
Lib/test/test_cmd_line.py
Lib/test/test_cmd_line.py
....
test_run_code (__main__.CmdLineTest) ... ok
....
OK


% env LANG=en_GB.UTF-8 ../Python-3.0rc3/python.exe 
Lib/test/test_cmd_line.py
....
test_run_code (__main__.CmdLineTest) ... ok
....
OK