reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
        git fetch tip x86/core
        git checkout tip/x86/core
        b4 shazam https://lore.kernel.org/r/20231009051740.17683-1-srikar@linux.vnet.ibm.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/bin/make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/bin/make.cross W=1 O=build_dir ARCH=powerpc prepare