flaky mDNS test: TestOtherDiscovery

[marten-seemann]

=== RUN   TestOtherDiscovery
      mdns_test.go:99: 
          	Error Trace:	mdns_test.go:99
          	Error:      	Condition never satisfied
          	Test:       	TestOtherDiscovery
          	Messages:   	expected peers to find each other
  --- FAIL: TestOtherDiscovery (26.31s)

[cbegin]

This looks like the same issue I'm seeing on MacOS. mDNS simply does not seem to work at all. I tried reimplementing the mDNS example code, and also ran this same test. Both seem to indicate that mDNS is not functional and isn't discovering peers. The debug logs simply iterate forever with the following lines (since I'm using 0.0.0.0). If I specify 127.0.0.1, the results are the same, except that it will lack the adding lines, since the address was specified. There's no other activity. Tried on two different networks. Haven't tried on a different computer.

2021-09-13T10:02:00.595-0600    DEBUG   addrutil        go-addr-util/addr.go:109        ResolveUnspecifiedAddresses:[/p2p-circuit /ip4/0.0.0.0/tcp/54893] [/ip4/10.8.1.113 /ip4/127.0.0.1 /ip6/::1] [/p2p-circuit /ip4/10.8.1.113/tcp/54893 /ip4/127.0.0.1/tcp/54893]
2021-09-13T10:02:05.595-0600    DEBUG   addrutil        go-addr-util/addr.go:64 adding resolved addr:/ip4/0.0.0.0/tcp/54893 /ip4/10.8.1.113/tcp/54893 [/ip4/10.8.1.113/tcp/54893]
2021-09-13T10:02:05.595-0600    DEBUG   addrutil        go-addr-util/addr.go:64 adding resolved addr:/ip4/0.0.0.0/tcp/54893 /ip4/127.0.0.1/tcp/54893 [/ip4/10.8.1.113/tcp/54893 /ip4/127.0.0.1/tcp/54893]
2021-09-13T10:02:05.595-0600    DEBUG   addrutil        go-addr-util/addr.go:109        ResolveUnspecifiedAddresses:[/p2p-circuit /ip4/0.0.0.0/tcp/54893] [/ip4/10.8.1.113 /ip4/127.0.0.1 /ip6/::1] [/p2p-circuit /ip4/10.8.1.113/tcp/54893 /ip4/127.0.0.1/tcp/54893]

[Stebalien]

@cbegin please file a new bug.