It seems that this buildbot failure is related to this issue:

https://buildbot.python.org/all/#/builders/105/builds/192


1 test failed:
    test_regrtest
43 tests skipped:
    test_aepack test_al test_applesingle test_bsddb185 test_bsddb3
    test_cd test_cl test_commands test_crypt test_curses test_dbm
    test_dl test_epoll test_fcntl test_fork1 test_gdb test_gdbm
    test_gl test_grp test_imgfile test_ioctl test_kqueue
    test_linuxaudiodev test_macos test_macostools test_mhlib test_nis
    test_openpty test_ossaudiodev test_pipes test_poll test_posix
    test_pty test_pwd test_readline test_resource test_scriptpackages
    test_spwd test_sunaudiodev test_threadsignals test_wait3
    test_wait4 test_zipfile64
2 skips unexpected on win32:
    test_gdb test_readline
1 re-run test:
    test_regrtest
Total duration: 29 min 51 sec
Tests result: FAILURE then FAILURE
test test_regrtest failed -- Traceback (most recent call last):
  File "d:\cygwin\home\db3l\buildarea\2.7.bolen-windowsvs9\build\lib\test\test_regrtest.py", line 662, in test_env_changed
    self.check_executed_tests(output, [testname], env_changed=testname)
  File "d:\cygwin\home\db3l\buildarea\2.7.bolen-windowsvs9\build\lib\test\test_regrtest.py", line 140, in check_executed_tests
    self.check_line(output, regex)
  File "d:\cygwin\home\db3l\buildarea\2.7.bolen-windowsvs9\build\lib\test\test_regrtest.py", line 87, in check_line
    self.assertRegexpMatches(output, regex)
AssertionError: Regexp didn't match: '^1 test altered the execution environment:\\n    test_regrtest_noop33$' not found in 'Run tests sequentially\n0:00:00 [1/1] test_regrtest_noop33\n\n== Tests result: SUCCESS ==\n\n1 test OK.\n\nTotal duration: 20 ms\nTests result: SUCCESS\n'


Both failures mention "test_regrtest_noop33".