reproduce (this is a W=1 build):
        git remote add openeuler https://gitee.com/openeuler/kernel.git
        git fetch --no-tags openeuler openEuler-1.0-LTS
        git checkout 221a9ce1bd3b42ba2226d22663110aed96ae471b
        # 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 arch/x86/ drivers/ kernel/ lib/