Poetry 1.4.0 installation fails
Cut a PR upstream to fix `pydata-sphinx-theme` wheels: https://github.com/pradyunsg/sphinx-theme-builder/pull/39
`poetry install -E all` fails with Poetry >=1.4.0 due to upstream incompatibility between `poetry>=1.4.0` and `pydata_sphinx_theme`. 

This is a tracking issue. I've already created an issue upstream here: https://github.com/pydata/pydata-sphinx-theme/issues/1253