It looks like the failure is random. It probably depends on the test order.

http://buildbot.python.org/all/builders/s390x%20SLES%203.4/builds/45/steps/test/logs/stdio

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ERROR: test_strptime (test.datetimetester.TestDateTimeTZ_Pure)
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Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/test/datetimetester.py", line 1941, in test_strptime
    dt = strptime(dtstr, "%z %Z")
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/datetime.py", line 1607, in strptime
    return _strptime._strptime_datetime(cls, date_string, format)
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/_strptime.py", line 500, in _strptime_datetime
    tt, fraction = _strptime(data_string, format)
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/_strptime.py", line 337, in _strptime
    (data_string, format))
ValueError: time data '-0500 EST' does not match format '%z %Z'

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ERROR: test_strptime (test.datetimetester.TestDateTime_Pure)
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Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/test/datetimetester.py", line 1941, in test_strptime
    dt = strptime(dtstr, "%z %Z")
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/datetime.py", line 1607, in strptime
    return _strptime._strptime_datetime(cls, date_string, format)
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/_strptime.py", line 500, in _strptime_datetime
    tt, fraction = _strptime(data_string, format)
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/_strptime.py", line 337, in _strptime
    (data_string, format))
ValueError: time data '-0500 EST' does not match format '%z %Z'

======================================================================
ERROR: test_strptime (test.datetimetester.TestSubclassDateTime_Pure)
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Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/test/datetimetester.py", line 1941, in test_strptime
    dt = strptime(dtstr, "%z %Z")
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/datetime.py", line 1607, in strptime
    return _strptime._strptime_datetime(cls, date_string, format)
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/_strptime.py", line 500, in _strptime_datetime
    tt, fraction = _strptime(data_string, format)
  File "/home/dje/cpython-buildarea/3.4.edelsohn-sles-z/build/Lib/_strptime.py", line 337, in _strptime
    (data_string, format))
ValueError: time data '-0500 EST' does not match format '%z %Z'