issue_comments

nice work spencer!

I think I tracked down the root of this odd behavior in nc-time-axis; see SciTools/nc-time-axis#45 for more details.

I think this NumPy issue is related: https://github.com/numpy/numpy/issues/16939. https://github.com/numpy/numpy/pull/16943 was merged yesterday, which appears to have at least allowed this to continue to work for the time being: ```python

import numpy as np a = np.array([[1., 2.], [3., 4.]]) a[:, 0] = (np.array([0.]), np.array([3650.])) <stdin>:1: DeprecationWarning: setting an array element with a sequence. This was supported in some cases where the elements are arrays with a single element. For example np.array([1, np.array([2])], dtype=int). In the future this will raise the same ValueError as np.array([1, [2]], dtype=int). ``` Given that this will be deprecated, I think it's still worthwhile to investigate what's causing this upstream in matplotlib or nc-time-axis, but it should be safe to un-xfail these tests again.

xfailed with: https://github.com/pydata/xarray/pull/4271

Thanks for noting this @dcherian; it seems like there may have been a change in NumPy that caused this. E.g. with NumPy master this doesn't work: ```python

import numpy as np np.version '1.20.0.dev0+2d12d0c' a = np.array([[1., 2.], [3., 4.]]) a[:, 0] = (np.array([0.]), np.array([3650.])) Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: setting an array element with a sequence. The requested array would exceed the maximum number of dimension of 1. But with earlier versions of NumPy it does:python import numpy as np np.version '1.19.1' a = np.array([[1., 2.], [3., 4.]]) a[:, 0] = (np.array([0.]), np.array([3650.])) a array([[0.00e+00, 2.00e+00], [3.65e+03, 4.00e+00]]) ``` I'll need to investigate more to see whether this is something to bring up in the matplotlib or NumPy issue tracker (it could be nc-time-axis related too). I'm not sure if there's anything we can do in xarray to fix this. It's probably best to xfail these tests for the time being.