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://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git/commit/?id=ff74f987504fe90e88fdba8d80197202868ce342
        git remote add trace git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
        git fetch --no-tags trace ring-buffer/for-next
        git checkout ff74f987504fe90e88fdba8d80197202868ce342
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash fs/bcachefs/ kernel/trace/