reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        git remote add geert-m68k https://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k.git
        git fetch geert-m68k for-next
        git checkout geert-m68k/for-next
        b4 shazam https://lore.kernel.org/r/20240814154427.162475-2-willy@infradead.org
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash lib/