In VyOS 1.3:
set system static-host-mapping host-name myhost1 inet 10.0.0.1
set system static-host-mapping host-name myhost2 inet 2001:db8:abcd:10::1
$ host myhost1
myhost1 has address 10.0.0.1
$ host myhost2
host myhost2 not found: 3(NXDOMAIN)
Hopefully the problem is something simple to fix?
Thanks