r3flow_test stderr

/usr/lib/python2.7/xml/etree/ElementTree.py:1638: DeprecationWarning: This method of XMLParser is deprecated.  Define doctype() method on the TreeBuilder target.
  DeprecationWarning,
F.
======================================================================
FAIL: test_flowlines (__main__.FlowlineTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "raster3d/r3.flow/testsuite/r3flow_test.py", line 93, in test_flowlines
    self.assertRaster3dFitsUnivar('test_flowaccum', reference=flowaccum, precision=1e-6)
  File "etc/python/grass/gunittest/case.py", line 318, in assertRaster3dFitsUnivar
    precision=precision)
  File "etc/python/grass/gunittest/case.py", line 253, in assertModuleKeyValue
    self.fail(self._formatMessage(msg, stdMsg))
AssertionError: r3.univar map=test_flowaccum percentile=90.0 separator== -g difference:
mismatch values (key, reference, actual): [('coeff_var', 178.097935490306, 177.119169754436), ('max', 91, 89), ('range', 91, 89), ('stddev', 11.3685848821312, 11.3061070026581), ('variance', 129.244722222222, 127.828055555556)]
command: r3.univar map=test_flowaccum percentile=90.0 separator== -g {'map': 'test_flowaccum', 'separator': '=', 'flags': 'g'}

----------------------------------------------------------------------
Ran 2 tests in 0.869s
FAILED (failures=1)