Fix: Trick sphinx into installing sphinx 4 and furo

    # >=3.2.1 for https://github.com/sphinx-doc/sphinx/issues/8084

    CI_SUPPORT_SPHINX_VERSION_SPECIFIER=">=3.2.1"

  fi

  with_echo $PY_EXE -m pip install "sphinx$CI_SUPPORT_SPHINX_VERSION_SPECIFIER" \

  # Two separate installs to trick sphinx into not precisely enforcing dependencies.

  # At the time of this writing, furo says it only works with sphinx 3.x.

  # (but it seems 4.x is OK!) -AK, 2021-05-20

  with_echo $PY_EXE -m pip install furo sphinx-copybutton

  with_echo $PY_EXE -m pip install "sphinx$CI_SUPPORT_SPHINX_VERSION_SPECIFIER" \

  cd doc

  if test "$1" = "--no-check"; then