reproduce (this is a W=1 build):
        git checkout c30e80d68a7afb334fde7147ee0106f25dd58d3a
        b4 shazam https://lore.kernel.org/r/40da257176192dce3b271c45b6ce7dcaa15b06af.1768759292.git.marcelo.schmitt1@gmail.com

        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=$HOME/0day COMPILER=gcc-9.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/iio/dummy/