reproduce (this is a W=1 build):
        # https://github.com/brauner/linux/commit/1a5353e584154c66d8d8c520f0ae4cea9fd18195
        git remote add brauner-github https://github.com/brauner/linux.git
        git fetch --no-tags brauner-github work.mount.gp_on_demand.proposal
        git checkout 1a5353e584154c66d8d8c520f0ae4cea9fd18195

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash fs/