reproduce (this is a W=1 build):
        git remote add ceph-client https://github.com/ceph/ceph-client.git
        git fetch ceph-client testing
        git checkout ceph-client/testing
        b4 shazam https://lore.kernel.org/r/20240417160842.76665-9-ryncsn@gmail.com
        # 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 mm/