The test_rolling_wrapped_dask tests in test_dataarray.py are failing with dask master, e.g., as seen here:
https://travis-ci.org/pydata/xarray/jobs/527936531

I reproduced this locally. git bisect identified the culprit as dask/dask#4756.

The source of this issue on the xarray side appears to be these lines:

In particular, we are currently padded as an xarray.DataArray object, not a dask array. Changing this to padded.data shows that passing an actual dask array to dask_array_ops.rolling_window results in failing tests.

@fujiisoup @jhamman any idea what's going on here?