Found a intermittent test on UnicodeFileTests.test_rename method.

Python Version: Python 3.3.0b1
Hg commit hash: 3fbfa61634de
MacOS X version 10.6.8 

How can be reproduced:

bumblebee:~/dev/cpython[] $ for i in {1..10}; do ./python.exe  -m test test_pep277; done
[1/1] test_pep277
1 test OK.
[103867 refs]
[1/1] test_pep277
1 test OK.
[103867 refs]
[1/1] test_pep277
1 test OK.
[103867 refs]
[1/1] test_pep277
1 test OK.
[103867 refs]
[1/1] test_pep277
1 test OK.
[103867 refs]
[1/1] test_pep277
test test_pep277 failed -- Traceback (most recent call last):
  File "/Users/flavio.barbosa/dev/cpython/Lib/test/test_pep277.py", line 172, in test_rename
    os.rename("tmp", name)
FileNotFoundError: [Errno 2] No such file or directory: '@test_51143_tmp/8_曨曩曫'

1 test failed:
    test_pep277
[103879 refs]
[1/1] test_pep277
1 test OK.
[103867 refs]
[1/1] test_pep277
test test_pep277 failed -- Traceback (most recent call last):
  File "/Users/flavio.barbosa/dev/cpython/Lib/test/test_pep277.py", line 172, in test_rename
    os.rename("tmp", name)
FileNotFoundError: [Errno 2] No such file or directory: '@test_51145_tmp/3_Grüß-Gott'

1 test failed:
    test_pep277
[103879 refs]
[1/1] test_pep277
1 test OK.
[103867 refs]
[1/1] test_pep277
test test_pep277 failed -- Traceback (most recent call last):
  File "/Users/flavio.barbosa/dev/cpython/Lib/test/test_pep277.py", line 172, in test_rename
    os.rename("tmp", name)
FileNotFoundError: [Errno 2] No such file or directory: '@test_51147_tmp/6_にぽん'

1 test failed:
    test_pep277
[103879 refs]