reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git/commit/?id=5ec355855dbc2d67587b6a10fef52c6cd3b1716e
        git remote add sj https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git
        git fetch --no-tags sj damon/next
        git checkout 5ec355855dbc2d67587b6a10fef52c6cd3b1716e
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc SHELL=/bin/bash