test_r_viewshed stderr

etc/python/grass/lib/gis.py:797: DeprecationWarning: classic int division
  ('__val', c_ulong * (1024 / (8 * sizeof(c_ulong)))),
/usr/lib/python2.7/xml/etree/ElementTree.py:1627: DeprecationWarning: This method of XMLParser is deprecated.  Define doctype() method on the TreeBuilder target.
  DeprecationWarning,
E.
======================================================================
ERROR: setUpClass (__main__.TestViewshed)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "raster/r.viewshed/testsuite/test_r_viewshed.py", line 12, in setUpClass
    cls.runModule('g.region', raster='elevation')
  File "etc/python/grass/gunittest/case.py", line 953, in runModule
    errors=errors)
CalledModuleError: Module run 1 g.region ended with error
Process ended with non-zero return code g.region(raster=['elevation']). See the following errors:
ERROR: Raster map <elevation> not found

See available raster maps:
gmted2010
gmted2010.shade
landsat.blue
landsat.green
landsat.red
lst_2010_01_average_piemonte
lst_2010_02_average_piemonte
lst_2010_03_average_piemonte
lst_2010_04_average_piemonte
lst_2010_05_average_piemonte
lst_2010_06_average_piemonte
lst_2010_07_average_piemonte
lst_2010_08_average_piemonte
lst_2010_09_average_piemonte
lst_2010_10_average_piemonte
lst_2010_11_average_piemonte
lst_2010_12_average_piemonte
orbassano_orto.blue
orbassano_orto.green
orbassano_orto.red
orbassano_orto.rgb
srtm
srtm_grezzo
uso_suolo2007


----------------------------------------------------------------------
Ran 1 test in 0.578s
FAILED (errors=1)