[yt-dev] Issue #600: Mysterious failures in nosetests (yt_analysis/yt)

[Kacper Kowalik]

New issue 600: Mysterious failures in nosetests
https://bitbucket.org/yt_analysis/yt/issue/600/mysterious-failures-in-nosetests

Kacper Kowalik:

Once in a while unit tests fail with:


```
#!text

======================================================================
FAIL: Accessing_AbsDivV_8
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/tmp/foobar/yt-3.0/yt/data_objects/tests/test_fields.py", line 77, in __call__
    assert_array_almost_equal_nulp(v1, conv*field._function(field, dd2), 4)
  File "/usr/lib64/python2.7/site-packages/numpy/testing/utils.py", line 1241, in assert_array_almost_equal_nulp
    raise AssertionError(msg)
AssertionError: X and Y are not equal to 4 ULP (max is 7.35385e+16)
>>  raise AssertionError('X and Y are not equal to 4 ULP (max is 7.35385e+16)')

```

effect is possibly related to butterflies and/or whether conditions on Mt. Kilimanjaro. Daredevil who will be able to find solution to the problem may expect a suprise prize.