Dhcp6c -k parameter causing error

The -k parameter in the /usr/lib/systemd/system/dhcp6c@.service unit file is causing an error when dhcp6c starts.

Here is the unit file ExecStart line.
ExecStart=/usr/sbin/dhcp6c -D -k /run/dhcp6c/dhcp6c.%i.sock -c /run/dhcp6c/dhcp6c.%i.conf -p /run/dhcp6c/dhcp6c.%i.pid %i

The error:
Dec 15 17:25:50 vyos dhcp6c[12808]: dhcp6_ctl_authinit: failed to open /run/dhcp6c/dhcp6c.eth0.sock: No such file or directory

I can’t find any explanation for the -k option. Does anyone know what the -k option is for and why it might be causing an error?

Version: VyOS 1.4-rolling-202211260318

Hi @paul_s , this param described in wide-dhcpv6 source code https://salsa.debian.org/debian/wide-dhcpv6/-/blob/master/dhcp6c.c#L189