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/kees/linux.git/commit/?id=ac6eb1f5df288a356e73ab40d393a52cc2ec3ed1
        git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git
        git fetch --no-tags kees dev/next-20240618/kmem_buckets-v5
        git checkout ac6eb1f5df288a356e73ab40d393a52cc2ec3ed1
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=m68k prepare