reproduce (this is a W=1 build): git checkout 576482b55c19e7ec00e162a0fde4c4f1a95128c7 b4 shazam https://lore.kernel.org/r/20260519011450.1144935-2-utilityemal77@gmail.com # install s390 cross compiling tool for clang build # apt-get install binutils-s390x-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=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash kernel/bpf/