Don't warn when doing comparisons or arithmetic with NaN

[shoyer]

Pandas used to unilaterally disable NumPy's warnings for doing comparisons with NaN, but now it doesn't: pandas-dev/pandas#13109

See also http://stackoverflow.com/questions/41130138/why-is-invalid-value-encountered-in-greater-warning-thrown-in-python-xarray-fo/41147570#41147570

[max-sixty]

What's the preferred way of doing this? Same context manager technique as pandas? pandas-dev/pandas@ce61b3f

[shoyer]

Yes, using np.errstate(all='ignore') as a context manager.

But as I noted in the StackOverflow answer, I think we actually already fixed this warning. You can find context managers with np.errstate several places in the codebase now.

[max-sixty]

Is there a reason Travis would report them? While a lot of these are netCDF, there are a lot of NaN-related warnings:

From https://travis-ci.org/maxim-lian/xarray/jobs/346841400

xarray/tests/test_backends.py::NetCDF4DataTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::NetCDF4DataStoreAutocloseTrue::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::NetCDF4ViaDaskDataTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::NetCDF4ViaDaskDataTestAutocloseTrue::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::ScipyInMemoryDataTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_append_overwrite_values
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_append_write
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_coordinates_encoding
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_dataset_caching
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_dataset_compute
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_dropna
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_isel_dataarray
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_load
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_None_variable
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_boolean_dtype
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_bytes_with_fill_value
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_coordinates
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_endian
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_example_1_netcdf
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_float64_data
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_global_coordinates
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_mask_and_scale
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_object_dtype
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_string_data
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_string_encoded_characters
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_roundtrip_test_data
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_unsigned_roundtrip_mask_and_scale
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyInMemoryDataTestAutocloseTrue::test_zero_dimensional_variable
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFileObjectTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::ScipyFilePathTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_append_overwrite_values
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_append_write
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_coordinates_encoding
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_dataset_caching
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_dataset_compute
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_dropna
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_isel_dataarray
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_load
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_None_variable
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_boolean_dtype
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_bytes_with_fill_value
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_coordinates
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_endian
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_example_1_netcdf
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_float64_data
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_global_coordinates
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_mask_and_scale
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_object_dtype
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_string_data
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_string_encoded_characters
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_roundtrip_test_data
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_unsigned_roundtrip_mask_and_scale
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::ScipyFilePathTestAutocloseTrue::test_zero_dimensional_variable
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::NetCDF3ViaNetCDF4DataTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::NetCDF3ViaNetCDF4DataTestAutocloseTrue::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::NetCDF4ClassicViaNetCDF4DataTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::NetCDF4ClassicViaNetCDF4DataTestAutocloseTrue::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::GenericNetCDFDataTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::GenericNetCDFDataTestAutocloseTrue::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::H5NetCDFDataTest::test_complex
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/h5netcdf/legacyapi.py:93: FutureWarning: complex dtypes are supported by h5py, but not part of the NetCDF API. You are writing an HDF5 file that is not a valid NetCDF file! In the future, this will be an error, unless you set invalid_netcdf=True.
    chunks=chunksizes, fillvalue=fill_value, **kwds)
xarray/tests/test_backends.py::H5NetCDFDataTest::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_backends.py::OpenMFDatasetManyFilesTest::test_2_autoclose_scipy
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/io/netcdf.py:299: RuntimeWarning: Cannot close a netcdf_file opened with mmap=True, when netcdf_variables or arrays referring to its data still exist. All data arrays obtained from such files refer directly to data on disk, and must be copied before the file can be cleanly closed. (See netcdf_file docstring for more information on mmap.)
    ), category=RuntimeWarning)
xarray/tests/test_backends.py::TestRasterio::test_caching
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2415: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file) as actual:
xarray/tests/test_backends.py::TestRasterio::test_chunks
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2435: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file, chunks=(1, 2, 2)) as actual:
xarray/tests/test_backends.py::TestRasterio::test_indexing
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2346: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file, cache=False) as actual:
xarray/tests/test_backends.py::TestRasterio::test_no_mftime
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2508: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file, chunks=(1, 2, 2)) as actual:
xarray/tests/test_backends.py::TestRasterio::test_non_rectilinear
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2279: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file) as rioda:
xarray/tests/test_backends.py::TestRasterio::test_notransform
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2337: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file) as rioda:
xarray/tests/test_backends.py::TestRasterio::test_platecarree
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2299: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file) as rioda:
xarray/tests/test_backends.py::TestRasterio::test_serialization
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2251: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file) as rioda:
xarray/tests/test_backends.py::TestRasterio::test_utm
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2259: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file) as rioda:
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_backends.py:2269: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
    with xr.open_rasterio(tmp_file, parse_coordinates=False) as rioda:
xarray/tests/test_coding_times.py::TestDatetime::test_decode_cf_datetime_overflow
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_coding_times.py:106: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using dummy netcdftime.datetime objects instead, reason: dates out of range
    result = coding.times.decode_cf_datetime(day, units)
xarray/tests/test_conventions.py::TestDecodeCF::test_decode_cf_datetime_transition_to_invalid
  /home/travis/build/maxim-lian/xarray/xarray/coding/times.py:113: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using dummy netcdftime.datetime objects instead, reason: dates out of range
    result = decode_cf_datetime(example_value, units, calendar)
  /home/travis/build/maxim-lian/xarray/xarray/coding/variables.py:71: SerializationWarning: Unable to decode time axis into full numpy.datetime64 objects, continuing using dummy netcdftime.datetime objects instead, reason: dates out of range
    return self.func(self.array[key])
xarray/tests/test_conventions.py::TestCFEncodedDataStore::test_default_fill_value
  /home/travis/build/maxim-lian/xarray/xarray/conventions.py:751: SerializationWarning: saving variable x with floating point data as an integer dtype without any _FillValue to use for NaNs
    for k, v in iteritems(variables))
xarray/tests/test_dataarray.py::TestDataArray::test_groupby_math
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_dataarray.py:2034: FutureWarning: the order of the arguments on DataArray.to_dataset has changed; you now need to supply ``name`` as a keyword argument
    ds = array.coords['x'].to_dataset('X')
xarray/tests/test_dataarray.py::TestDataArray::test_reindex_regressions
  /home/travis/build/maxim-lian/xarray/xarray/core/dataarray.py:889: FutureWarning: Indexer has dimensions ('time2',) that are different from that to be indexed along time. This will behave differently in the future.
    method=method, tolerance=tolerance, copy=copy, **indexers)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-None-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-None-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-1-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-1-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-2-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-2-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-3-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[mean-1-3-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: Mean of empty slice
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-None-True-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-None-False-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-1-True-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-1-False-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-2-True-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-2-False-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-3-True-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[std-1-3-False-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/lib/nanfunctions.py:1434: RuntimeWarning: Degrees of freedom <= 0 for slice.
    keepdims=keepdims)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-None-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-None-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-1-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-1-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-2-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-2-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-3-True-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_dataarray.py::test_rolling_reduce[max-1-3-False-2]
  /home/travis/build/maxim-lian/xarray/xarray/core/variable.py:1224: RuntimeWarning: All-NaN slice encountered
    axis=axis, **kwargs)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-False-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-min-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-False-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-False-max-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-min-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-max-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[None-True-var-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-min-False-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-min-False-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-min-False-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-min-False-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:29: RuntimeWarning: invalid value encountered in reduce
    return umr_minimum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-max-False-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-max-False-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-max-False-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-False-max-False-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/numpy/core/_methods.py:26: RuntimeWarning: invalid value encountered in reduce
    return umr_maximum(a, axis, None, out, keepdims)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-min-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-max-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-float-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-float-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-int-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-int-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-float32-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-float32-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_reduce[x-True-var-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:297: RuntimeWarning: invalid value encountered in true_divide
    u = total / n
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/numpy_compat.py:48: RuntimeWarning: invalid value encountered in true_divide
    x = np.divide(x1, x2, out)
xarray/tests/test_duck_array_ops.py::test_argmin_max[x-True-min-True-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:490: RuntimeWarning: All-NaN slice encountered
    vals = func(x, axis=arg_axis, keepdims=True)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_argmin_max[x-True-min-True-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:490: RuntimeWarning: All-NaN slice encountered
    vals = func(x, axis=arg_axis, keepdims=True)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_argmin_max[x-True-max-True-True-bool_-1]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:490: RuntimeWarning: All-NaN slice encountered
    vals = func(x, axis=arg_axis, keepdims=True)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_argmin_max[x-True-max-True-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:490: RuntimeWarning: All-NaN slice encountered
    vals = func(x, axis=arg_axis, keepdims=True)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/compatibility.py:48: RuntimeWarning: All-NaN slice encountered
    return func(*args, **kwargs)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/toolz/functoolz.py:468: RuntimeWarning: All-NaN slice encountered
    ret = f(ret)
xarray/tests/test_duck_array_ops.py::test_argmin_max[y-True-min-True-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:490: RuntimeWarning: All-NaN slice encountered
    vals = func(x, axis=arg_axis, keepdims=True)
xarray/tests/test_duck_array_ops.py::test_argmin_max[y-True-max-True-True-bool_-2]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/array/reductions.py:490: RuntimeWarning: All-NaN slice encountered
    vals = func(x, axis=arg_axis, keepdims=True)
xarray/tests/test_missing.py::test_scipy_methods_function
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/interpolate/polyint.py:511: RuntimeWarning: overflow encountered in multiply
    self.wi[:j] *= (self.xi[j]-self.xi[:j])
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/interpolate/polyint.py:512: RuntimeWarning: overflow encountered in reduce
    self.wi[j] = np.multiply.reduce(self.xi[:j]-self.xi[j])
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/interpolate/polyint.py:609: RuntimeWarning: invalid value encountered in true_divide
    p = np.dot(c,self.yi)/np.sum(c,axis=-1)[...,np.newaxis]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/interpolate/polyint.py:324: RuntimeWarning: overflow encountered in multiply
    pi = w*pi
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/interpolate/polyint.py:325: RuntimeWarning: invalid value encountered in add
    p += pi[:,np.newaxis] * self.c[k]
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/scipy/interpolate/polyint.py:325: RuntimeWarning: invalid value encountered in multiply
    p += pi[:,np.newaxis] * self.c[k]
xarray/tests/test_plot.py::TestContourf::test_can_plot_all_nans
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1534: UserWarning: Warning: converting a masked element to nan.
    self.zmax = float(z.max())
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1535: UserWarning: Warning: converting a masked element to nan.
    self.zmin = float(z.min())
xarray/tests/test_plot.py::TestContour::test_can_plot_all_nans
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1534: UserWarning: Warning: converting a masked element to nan.
    self.zmax = float(z.max())
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1535: UserWarning: Warning: converting a masked element to nan.
    self.zmin = float(z.min())
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1176: RuntimeWarning: invalid value encountered in greater
    inside = (self.levels > self.zmin) & (self.levels < self.zmax)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1176: RuntimeWarning: invalid value encountered in less
    inside = (self.levels > self.zmin) & (self.levels < self.zmax)
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1180: UserWarning: No contour levels were found within the data range.
    warnings.warn("No contour levels were found"
xarray/tests/test_plot.py::TestContour::test_single_level
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/contour.py:1180: UserWarning: No contour levels were found within the data range.
    warnings.warn("No contour levels were found"
xarray/tests/test_plot.py::TestPcolormesh::test_can_plot_axis_size_one
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/axes/_base.py:2961: UserWarning: Attempting to set identical left==right results
  in singular transformations; automatically expanding.
  left=0.0, right=0.0
    'left=%s, right=%s') % (left, right))
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/matplotlib/axes/_base.py:3285: UserWarning: Attempting to set identical bottom==top results
  in singular transformations; automatically expanding.
  bottom=0.0, top=0.0
    'bottom=%s, top=%s') % (bottom, top))
xarray/tests/test_variable.py::TestVariable::test_index_0d_not_a_time
  /home/travis/build/maxim-lian/xarray/xarray/core/duck_array_ops.py:138: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    flag_array = (arr1 == arr2)
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_variable.py:144: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    assert variable.values[0] == expected_value0
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_variable.py:145: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    assert variable[0].values == expected_value0
xarray/tests/test_variable.py::TestVariableWithDask::test_index_0d_not_a_time
  /home/travis/miniconda/envs/test_env/lib/python3.6/site-packages/dask/local.py:271: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    return func(*args2)
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_variable.py:144: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    assert variable.values[0] == expected_value0
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_variable.py:145: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    assert variable[0].values == expected_value0
xarray/tests/test_variable.py::TestIndexVariable::test_index_0d_not_a_time
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_variable.py:144: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    assert variable.values[0] == expected_value0
  /home/travis/build/maxim-lian/xarray/xarray/tests/test_variable.py:145: FutureWarning: In the future, 'NAT == x' and 'x == NAT' will always be False.
    assert variable[0].values == expected_value0

[shoyer]

It looks like we only silenced the warnings in comparisons/arithmetic, but not reductions.

[jhamman]

Right, I think we left #1652 to continue work on the reductions / other warnings.

[max-sixty]

Right, I seem to be losing my memory - I put a comment in #1652 literally 8 days ago. Almost as much noise as the warnings output...