Documentation build is failing

[bouweandela]

The documentation fails to build since a week or two. It looks like something is going wrong with an import.

The same problem appeared on CircleCI, but there it seems to have solved itself after a few failed builds about two weeks ago: https://app.circleci.com/pipelines/github/ESMValGroup/ESMValTool?branch=main

Stack trace from CircleCI:

autodoc: failed to import module 'compute_eofs' from module 'esmvaltool.diag_scripts.monitor'; the following exception was raised:
Traceback (most recent call last):
  File "/opt/conda/envs/esmvaltool/lib/python3.10/site-packages/sphinx/ext/autodoc/importer.py", line 61, in import_module
    return importlib.import_module(modname)
  File "/opt/conda/envs/esmvaltool/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/root/project/esmvaltool/diag_scripts/monitor/compute_eofs.py", line 54, in <module>
    from esmvaltool.diag_scripts.monitor.monitor_base import MonitorBase
  File "/root/project/esmvaltool/diag_scripts/monitor/monitor_base.py", line 11, in <module>
    from mapgenerator.plotting.timeseries import PlotSeries
  File "/opt/conda/envs/esmvaltool/lib/python3.10/site-packages/mapgenerator/plotting/timeseries.py", line 203, in <module>
    class YearLocator(mdates.DateLocator):
  File "/opt/conda/envs/esmvaltool/lib/python3.10/site-packages/mapgenerator/plotting/timeseries.py", line 270, in YearLocator
    @cbook.deprecated("3.2")
  File "/opt/conda/envs/esmvaltool/lib/python3.10/site-packages/matplotlib/_api/__init__.py", line 224, in __getattr__
    raise AttributeError(
AttributeError: module 'matplotlib.cbook' has no attribute 'deprecated'

[bouweandela]

@valeriupredoi Would you have time to take a look at this?

[valeriupredoi]

@bouweandela it's been discussed here, bud #2800

[bouweandela]

Thanks! I already thought I saw a mention of this problem somewhere, but couldn't find the issue.

[valeriupredoi]

let me close this if that's OK with you @bouweandela - am gonna change the title to #2800 have it mention the docs build fails (for bookkeeping)