CI failure downloading external data

[crusaderky]

The 'Docs' ci project is failing because http://naciscdn.org is unresponsive:

https://dev.azure.com/xarray/xarray/_build/results?buildId=408&view=logs&jobId=7e620c85-24a8-5ffa-8b1f-642bc9b1fc36

Excerpt:

/usr/share/miniconda/envs/xarray-tests/lib/python3.7/site-packages/cartopy/io/__init__.py:260: DownloadWarning: Downloading: http://naciscdn.org/naturalearth/110m/physical/ne_110m_coastline.zip
  warnings.warn('Downloading: {}'.format(url), DownloadWarning)

Exception occurred:
  File "/usr/share/miniconda/envs/xarray-tests/lib/python3.7/urllib/request.py", line 1319, in do_open
    raise URLError(err)
urllib.error.URLError: <urlopen error [Errno 110] Connection timed out>
The full traceback has been saved in /tmp/sphinx-err-nq73diee.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
##[error]Bash exited with code '2'.
##[section]Finishing: Build HTML docs

[max-sixty]

Thanks @crusaderky . This now passed .

If this happens regularly, we could try and remove from the Docs, or allow that to pass regardless. Shall we see if we get it again?

[crusaderky]

Closing for now