Setting up samba4 (4.0.0~alpha18.dfsg1-4ubuntu1) ...
ERROR: Invalid smb.conf
ERROR: Invalid smb.conf
Administrator password will be set randomly!
ProvisioningError: guess_names: 'realm =' was not specified in supplied /etc/samba/smb.conf.  Please remove the smb.conf file and let provision generate it
dpkg: error processing samba4 (--configure):
 subprocess installed post-installation script returned error exit status 1