`test_p2p.py` (local P2P test) fails even on non-symmetric mode

[copyrat90]

Issue

I saw the issues regarding P2P (#247, #354), but those issues are about the remote environment. They at least worked on the same machine (i.e. succeeds test_p2p.py).

But on my Windows 11 machine, even the test_p2p.py (i.e. the same machine P2P test) fails with non-symmetric mode.

I git bisected to figure out that it worked on ea429d4, but it doesn't work after 38db88f.

Log for 38db88f (doesn't work)

38db88f-fail.log

Log for ea429d4 (works)

ea429d45-success.log

Differences

Looking at the logs above, looks like the failed attempt doesn't get a rendezvous candidate for IPv6 link-local address.