when yast2-printer calls /usr/lib/YaST2/bin/cups_client_only
without any parameter the script hangs for about 30 seconds at
 lpstat -h -p

I noticed it with CUPS 2.1.0:
----------------------------------------------------------------------------
# time lpstat -h -p
lpstat: No such file or directory

real    0m35.051s
user    0m0.004s
sys     0m0.014s

# time lpstat -p
printer hl5150ljet4 is idle.  enabled since Tue 01 Sep 2015 14:01:39 CEST

real    0m0.017s
user    0m0.008s
sys     0m0.007s
----------------------------------------------------------------------------

The reason is in /usr/lib/YaST2/bin/cups_client_only that the line
----------------------------------------------------------------------------
   if lpstat -h $SERVERNAME -p
----------------------------------------------------------------------------
is called with empty $SERVERNAME.