reproduce (this is a W=1 build):
        git remote add hch-xfs git://git.infradead.org/users/hch/xfs
        git fetch --no-tags hch-xfs xfs-zoned-rebase
        git checkout 7d0ae5c0dcfc39db9e13893a83d1947d042b3d4a
        # 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