reproduce (this is a W=1 build):
        # https://github.com/scosu/linux-sched/commit/a930c4a21ccd537fdaf4c2ff6e18172fc0d626a8
        git remote add scosu-sched https://github.com/scosu/linux-sched
        git fetch --no-tags scosu-sched topic/mmap-cap-prot-wip/v6.18
        git checkout a930c4a21ccd537fdaf4c2ff6e18172fc0d626a8

        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=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=xtensa olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=xtensa SHELL=/bin/bash mm/