reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://github.com/alexshi/linux/commit/887c1bf7c199edf9083e31d7959f92735d410ec9
        git remote add alexshi https://github.com/alexshi/linux.git
        git fetch --no-tags alexshi mmunstable
        git checkout 887c1bf7c199edf9083e31d7959f92735d410ec9
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash mm/