reproduce (this is a W=1 build):
        git remote add brauner-vfs https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
        git fetch brauner-vfs vfs.all
        git checkout brauner-vfs/vfs.all
        b4 shazam https://lore.kernel.org/r/20260310000826.242674-1-contact@gvernon.com

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install sparse
        # sparse: v0.6.5-rc1

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.5.0 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=microblaze olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.5.0 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=microblaze SHELL=/bin/bash fs/hfs/