reproduce (this is a W=1 build):
        git remote add samba-ksmbd git://git.samba.org/ksmbd.git
        git fetch --no-tags samba-ksmbd for-next
        git checkout f4efd0937eeb59de552bcfab2305e19b2a381913
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/smb/client/