Similar failed test today (not close to midnight) with Roundup 1.5.0+:

Failure in test testFilteringRangeGeekInterval
(test.test_postgresql.postgresqlDBTest)
Traceback (most recent call last):                 
  File "/usr/lib/python2.7/unittest/case.py", line 332, in run
    testMethod()
  File "/home/intevation/roundup/roundup.hg/./test/db_test_base.py",
line 1350, in testFilteringRangeGeekInterval
    ae(filt(None, {'deadline': '-1d;'}), ['6'])
  File "/usr/lib/python2.7/unittest/case.py", line 516, in assertEqual
    assertion_func(first, second, msg=msg)
  File "/usr/lib/python2.7/unittest/case.py", line 745, in assertListEqual
    self.assertSequenceEqual(list1, list2, msg, seq_type=list)
  File "/usr/lib/python2.7/unittest/case.py", line 727, in
assertSequenceEqual
    self.fail(msg)
  File "/usr/lib/python2.7/unittest/case.py", line 413, in fail
    raise self.failureException(msg)
AssertionError: Lists differ: [] != ['6']

Second list contains 1 additional elements.
First extra element 0:
6

- []
+ ['6']


The same change was already reported for 1.3.0:
http://osdir.com/ml/bug-tracking.roundup.devel/2006-11/msg00038.html

But it is not easily reproducible, it did not show up on 10 further runs of:
python run_tests.py . testFilteringRangeGeekInterval