reproduce:
        # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linus-next.git/commit/?id=f2d46684be2201e54c088728e741b71aa33b2aa5
        git remote add sashal-linus-next https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linus-next.git
        git fetch --no-tags sashal-linus-next linus-next
        git checkout f2d46684be2201e54c088728e741b71aa33b2aa5
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs