reproduce (this is a W=1 build):
        # https://github.com/linuxppc/linux/commit/11d09e46b796ac14f24ab63de2c0185a307b2054
        git remote add linuxppc https://github.com/linuxppc/linux
        git fetch --no-tags linuxppc merge-test
        git checkout 11d09e46b796ac14f24ab63de2c0185a307b2054

        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=$HOME/0day COMPILER=gcc-16.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-16.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kernel/