test_table stderr

/usr/lib/python2.7/dist-packages/numpy/core/__init__.py:6: DeprecationWarning: CObject type is not supported in 3.x. Please use capsule objects instead.
  from . import multiarray
/usr/lib/python2.7/dist-packages/numpy/core/__init__.py:7: DeprecationWarning: CObject type is not supported in 3.x. Please use capsule objects instead.
  from . import umath
etc/python/grass/lib/gis.py:803: DeprecationWarning: classic int division
  ('__val', c_ulong * (1024 / (8 * sizeof(c_ulong)))),
EEEE
======================================================================
ERROR: test_check_insert_update_str (__main__.ColumnsTestCase)
Check insert_str and update_str attribute of Columns are correct
----------------------------------------------------------------------
Traceback (most recent call last):
  File "lib/python/pygrass/vector/testsuite/test_table.py", line 144, in tearDown
    self.table.drop(force=True)
  File "etc/python/grass/pygrass/vector/table.py", line 1025, in drop
    if len(used) > 0 and not force:
TypeError: object of type 'NoneType' has no len()

======================================================================
ERROR: test_insert (__main__.TableInsertTestCase)
Test Table.insert method
----------------------------------------------------------------------
Traceback (most recent call last):
  File "lib/python/pygrass/vector/testsuite/test_table.py", line 168, in tearDown
    self.table.drop(force=True)
  File "etc/python/grass/pygrass/vector/table.py", line 1025, in drop
    if len(used) > 0 and not force:
TypeError: object of type 'NoneType' has no len()

======================================================================
ERROR: test_insert_many (__main__.TableInsertTestCase)
Test Table.insert method using many==True
----------------------------------------------------------------------
Traceback (most recent call last):
  File "lib/python/pygrass/vector/testsuite/test_table.py", line 168, in tearDown
    self.table.drop(force=True)
  File "etc/python/grass/pygrass/vector/table.py", line 1025, in drop
    if len(used) > 0 and not force:
TypeError: object of type 'NoneType' has no len()

======================================================================
ERROR: test_update (__main__.TableUpdateTestCase)
Test Table.update method
----------------------------------------------------------------------
Traceback (most recent call last):
  File "lib/python/pygrass/vector/testsuite/test_table.py", line 144, in tearDown
    self.table.drop(force=True)
  File "etc/python/grass/pygrass/vector/table.py", line 1025, in drop
    if len(used) > 0 and not force:
TypeError: object of type 'NoneType' has no len()

----------------------------------------------------------------------
Ran 4 tests in 2.385s
FAILED (errors=4)