docs builds are broken

[dcherian]

What happened?

Traceback (most recent call last):
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/site-packages/nbsphinx/__init__.py", line 634, in parse
    rststring, resources = exporter.from_notebook_node(nb, resources)
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/site-packages/nbsphinx/__init__.py", line 397, in from_notebook_node
    nb, resources = pp.preprocess(nb, resources)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/site-packages/nbconvert/preprocessors/execute.py", line 103, in preprocess
    self.preprocess_cell(cell, resources, index)
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/site-packages/nbconvert/preprocessors/execute.py", line 124, in preprocess_cell
    cell = self.execute_cell(cell, index, store_history=True)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/site-packages/jupyter_core/utils/__init__.py", line 165, in wrapped
    return loop.run_until_complete(inner)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/asyncio/base_events.py", line 687, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/site-packages/nbclient/client.py", line 1062, in async_execute_cell
    await self._check_raise_for_error(cell, cell_index, exec_reply)
  File "/home/docs/checkouts/readthedocs.org/user_builds/xray/conda/9766/lib/python3.12/site-packages/nbclient/client.py", line 918, in _check_raise_for_error
    raise CellExecutionError.from_cell_and_msg(cell, exec_reply_content)
nbclient.exceptions.CellExecutionError: An error occurred while executing the following cell:
------------------
ds = xr.tutorial.load_dataset("era5-2mt-2019-03-uk.grib", engine="cfgrib")
------------------

HTTPError: 403 Client Error: Forbidden for url: https://raw.githubusercontent.com/pydata/xarray-data/master/era5-2mt-2019-03-uk.grib

What did you expect to happen?

No response

Minimal Complete Verifiable Example

No response

MVCE confirmation

• [ ] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
• [ ] Complete example — the example is self-contained, including all data and the text of any traceback.
• [ ] Verifiable example — the example copy & pastes into an IPython prompt or Binder notebook, returning the result.
• [ ] New issue — a search of GitHub Issues suggests this is not a duplicate.
• [ ] Recent environment — the issue occurs with the latest version of xarray and its dependencies.

Relevant log output

No response

Anything else we need to know?

No response

Environment

[kmuehlbauer]

This issue is not only affecting xarray, also other projects hosted on RTD experience these download issues. Not idea how to tackle this, since the data downloads perfectly fine locally.

pooch also didn't have an update recently, ruling that out as an issue. Maybe some other dependencies have changed in the network stack?

[kmuehlbauer]

XRef:

• https://github.com/readthedocs/readthedocs.org/issues/11763
• https://github.com/scipy/scipy/issues/21879
• https://github.com/openradar/xradar/pull/240#issuecomment-2474905416

[kmuehlbauer]

This is some weird upstream issue between RTD and GitHub AFAICT, see https://github.com/readthedocs/readthedocs.org/issues/11763#issuecomment-2476333955 for a summary.

[phofl]

Dask fixed this here: https://github.com/dask/dask-sphinx-theme/pull/91