reproduce (this is a W=1 build):
        git remote add cifs git://git.samba.org/sfrench/cifs-2.6.git
        git fetch --no-tags cifs 5.15-backport-8-1-24
        git checkout cb470770db4ecdaf46a6c4b1703889ba2d6a4b19
        # 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/