reproduce:
        git remote add broonie-regulator https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git
        git fetch broonie-regulator for-next
        git checkout broonie-regulator/for-next
        b4 shazam https://lore.kernel.org/r/20240830110732.30080-1-macpaul.lin@mediatek.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 2.4.4
        make htmldocs