Fix last remaining reference warnings

Enable nitpicky mode in CI to error on missing references.

Author: maarten-ic

ci/build_docs_and_dist.sh

@@ -33,6 +33,11 @@ pip install "`readlink -f dist/*.whl`[docs]"
 # Debugging:
 pip freeze
 
+# Enable sphinx options:
+# - `-W`: turn warnings into errors
+# - `-n`: nit-picky mode, warn about all missing references
+# - `--keep-going`: with -W, keep going when getting warnings
+export SPHINXOPTS='-W -n --keep-going'
+
 # Run sphinx to create the documentation
-export SPHINXOPTS='-W --keep-going'  # Treat all warnings as errors
 make -C docs clean html

docs/source/conf.py

@@ -416,6 +416,7 @@
     # "pandas": ("https://pandas.pydata.org/pandas-docs/stable", None),
     "numpy": ("https://numpy.org/doc/stable", None),
     "scipy": ("https://docs.scipy.org/doc/scipy/reference", None),
+    "packaging": ("https://packaging.pypa.io/en/stable/", None),
     # "numba": ("https://numba.pydata.org/numba-doc/latest", None),
     # "matplotlib": ("https://matplotlib.org", None),
     # "xarray": ("http://xarray.pydata.org/en/stable/", None),