reproduce (this is a W=1 build):
        git remote add opencloudos https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
        git fetch --no-tags opencloudos linux-5.4/next
        git checkout ba1503e9ed8f70dee78545c9b49425be956deea8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash