reproduce:
        git checkout 33a647c659ffa5bdb94abc345c8c86768ff96215
        b4 shazam https://lore.kernel.org/r/20260130005739.3163049-2-jasonmiu@google.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs