mount will not mount network filesystems

Binary package hint: mount

nfs and cifs filesystems no longer work after upgrading mount last night:

root@wile-e-coyote:~# mount -v -o rw -t cifs agatha:/home /home
mount: wrong fs type, bad option, bad superblock on agatha:/home,
       missing codepage or other error
       In some cases useful info is found in syslog - try
       dmesg | tail or so

root@wile-e-coyote:~# mount -v -o rw -t nfs agatha:/home /home
mount: wrong fs type, bad option, bad superblock on agatha:/home,
       missing codepage or other error
       In some cases useful info is found in syslog - try
       dmesg | tail or so

There's nothing of note in the syslog or dmesg.