New warnings in numpy wheels nightly builds. #18721

core/tests/test_regression.py::TestRegression::test_object_array_from_list
  /venv/lib/python3.7/site-packages/numpy/core/tests/test_regression.py:507: FutureWarning: Promotion of numbers and bools to strings is deprecated. In the future, code such as `np.concatenate((['string'], [0]))` will raise an error, while `np.asarray(['string', 0])` will return an array with `dtype=object`.  To avoid the warning while retaining a string result use `dtype='U'` (or 'S').  To get an array of Python objects use `dtype=object`. (Warning added in NumPy 1.21)
    assert_(np.array([1, 'A', None]).shape == (3,))

core/tests/test_regression.py::TestRegression::test_string_truncation
  /venv/lib/python3.7/site-packages/numpy/core/tests/test_regression.py:2058: FutureWarning: Promotion of numbers and bools to strings is deprecated. In the future, code such as `np.concatenate((['string'], [0]))` will raise an error, while `np.asarray(['string', 0])` will return an array with `dtype=object`.  To avoid the warning while retaining a string result use `dtype='U'` (or 'S').  To get an array of Python objects use `dtype=object`. (Warning added in NumPy 1.21)
    b = np.array([val, tostr('xx')])

core/tests/test_regression.py::TestRegression::test_string_truncation
  /venv/lib/python3.7/site-packages/numpy/core/tests/test_regression.py:2060: FutureWarning: Promotion of numbers and bools to strings is deprecated. In the future, code such as `np.concatenate((['string'], [0]))` will raise an error, while `np.asarray(['string', 0])` will return an array with `dtype=object`.  To avoid the warning while retaining a string result use `dtype='U'` (or 'S').  To get an array of Python objects use `dtype=object`. (Warning added in NumPy 1.21)
    b = np.array([tostr('xx'), val])

core/tests/test_regression.py::TestRegression::test_string_truncation
  /venv/lib/python3.7/site-packages/numpy/core/tests/test_regression.py:2064: FutureWarning: Promotion of numbers and bools to strings is deprecated. In the future, code such as `np.concatenate((['string'], [0]))` will raise an error, while `np.asarray(['string', 0])` will return an array with `dtype=object`.  To avoid the warning while retaining a string result use `dtype='U'` (or 'S').  To get an array of Python objects use `dtype=object`. (Warning added in NumPy 1.21)
    b = np.array([val, tostr('xxxxxxxxxx')])

core/tests/test_regression.py::TestRegression::test_string_truncation
  /venv/lib/python3.7/site-packages/numpy/core/tests/test_regression.py:2066: FutureWarning: Promotion of numbers and bools to strings is deprecated. In the future, code such as `np.concatenate((['string'], [0]))` will raise an error, while `np.asarray(['string', 0])` will return an array with `dtype=object`.  To avoid the warning while retaining a string result use `dtype='U'` (or 'S').  To get an array of Python objects use `dtype=object`. (Warning added in NumPy 1.21)
    b = np.array([tostr('xxxxxxxxxx'), val])

ma/tests/test_mrecords.py::TestMRecordsImport::test_fromarrays
  /venv/lib/python3.7/site-packages/numpy/ma/core.py:2826: FutureWarning: Promotion of numbers and bools to strings is deprecated. In the future, code such as `np.concatenate((['string'], [0]))` will raise an error, while `np.asarray(['string', 0])` will return an array with `dtype=object`.  To avoid the warning while retaining a string result use `dtype='U'` (or 'S').  To get an array of Python objects use `dtype=object`. (Warning added in NumPy 1.21)
    order=order, subok=True, ndmin=ndmin)