reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git/commit/?id=345e029b561e03c4647b3d5b6603f40745a2ac92
        git remote add tj-wq https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git
        git fetch --no-tags tj-wq tmp2
        git checkout 345e029b561e03c4647b3d5b6603f40745a2ac92
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv prepare