bs4
# pin setuptools<81 so pkg_resources (used by notedown) remains available
setuptools<81
# d2lbook pins sphinxcontrib-bibtex<2.0.0, but that version's oset dep
# uses collections.MutableSet which was removed in Python 3.10.
# We override it here (installed after d2lbook to win the conflict).
sphinxcontrib-bibtex>=2.5.0