reproduce:
        git remote add openeuler https://gitee.com/openeuler/kernel.git
        git fetch --no-tags openeuler OLK-6.6
        git checkout c3d1c3ac9ce3b71e515f8b310a892116272222ec
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs