reproduce:
        git checkout linus/master
        b4 shazam https://lore.kernel.org/r/20241002011147.1345-1-shenghao-ding@ti.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 2.4.4
        make htmldocs