reproduce:
        git checkout ab27740f76654ed58dd32ac0ba0031c18a6dea3b
        b4 shazam https://lore.kernel.org/r/20240702-mainline_sdp500-v3-3-0902047b3eee@gmail.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 2.4.4
        make htmldocs