reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha.git/commit/?id=b74843b38da8f1186fd7d447646c835b47096a15
        git remote add mattst88-alpha https://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha.git
        git fetch --no-tags mattst88-alpha alpha-fp-tininess
        git checkout b74843b38da8f1186fd7d447646c835b47096a15

        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=$HOME/0day COMPILER=gcc-12.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/math-emu/ mm/