reproduce (this is a W=1 build):
        # https://github.com/brauner/linux/commit/56749ed317e256c6dc3ca83e246fc17479366f83
        git remote add brauner-github https://github.com/brauner/linux.git
        git fetch --no-tags brauner-github vfs-6.19.iomap
        git checkout 56749ed317e256c6dc3ca83e246fc17479366f83

        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=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash fs/overlayfs/