reproduce (this is a W=1 build):
        # https://github.com/amir73il/linux/commit/541b457050a7e09c98f9e1a0b5a063037bd8c50e
        git remote add amir73il https://github.com/amir73il/linux
        git fetch --no-tags amir73il vfs-6.19.ovl
        git checkout 541b457050a7e09c98f9e1a0b5a063037bd8c50e

        # install sparc64 cross compiling tool for clang build
        # apt-get install binutils-sparc64-linux-gnu
        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=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc64 SHELL=/bin/bash fs/