reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # https://github.com/intel/linux-intel-lts/commit/c7f2087e27ce6a3052f8f9f38b790f2408bcd052
        git remote add intel-lts https://github.com/intel/linux-intel-lts.git
        git fetch --no-tags intel-lts 6.6/preempt-rt
        git checkout c7f2087e27ce6a3052f8f9f38b790f2408bcd052
        # save the config file
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 ARCH=s390