reproduce:
        git checkout 8e7460eac786c72f48c4e04ce9be692b939428ce
        b4 shazam https://lore.kernel.org/r/20251222-vkms-all-config-v3-18-ba42dc3fb9ff@bootlin.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs