setsockopt IPV6_TCLASS 16: Protocol not avail

When I ssh into my Linode recently, the first two lines I see are:

setsockopt IPV6_TCLASS 16: Protocol not available:

Welcome to Ubuntu 12.04.4 LTS (GNU/Linux 3.12.9-x8664-linode37 x8664)

I have not seen this first line previously.

However, when I check my login with w I do see that my local IPV6 indeed is logged in fine as it has been for years.

Linode tech support does not understand this message either. They have checked my Linode IPv6 address and it seems fine at their end.

When I check my rsync logs, I also see

setsockopt IPV6_TCLASS 8: Protocol not available:

My rsync logs show this has been happening since 19 March 2014.

Has anyone else started seeing something like this?