Apologies seems this was already reported and marked as resolved ( https://phabricator.vyos.net/T1053 )
When removing the DHCP option from an interface address the following error message is given
vyos@vyos# delete interfaces ethernet eth0 address dhcp
[ interfaces ethernet eth0 address dhcp ]
Traceback (most recent call last):File "/usr/libexec/vyos/system/normalize-ip", line 32, in <module> address_string, prefix_length = re.match(r'(.+)/(.+)', sys.argv).groups()
AttributeError: 'NoneType' object has no attribute 'groups'
Stopping DHCP client on eth0 ...