reproduce (this is a W=1 build):
        # https://github.com/scosu/linux-sched/commit/b8dd58a99f3a6b933636441f72da97e1a06c8a57
        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 b8dd58a99f3a6b933636441f72da97e1a06c8a57

        # install um cross compiling tool for clang build
        # apt-get install binutils-um-linux-gnu
        # clang-23 might not be officially released. Try a lower version if installation fails.
        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=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=um olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=um SHELL=/bin/bash arch/um/os-Linux/skas/ block/ fs/ io_uring/ kernel/ lib/