Tons of "sa6_recoverscope: assumption failure" on recent -current

[Andrey Chernov]

On every IPv6 address of my card and router and every broadcast and
link-local scope addresses I see now:
kernel: sa6_recoverscope: assumption failure (non 0 ID): <ipv6 address>

What does it mean and why there are so many of them? I have plain local
net with IPv6 router, nothing unusual.

IPv6 continues to work despite of those failures.