Comment 4 for bug 2039374

Ok, I better understand why this has never shown up in most situations.

> my system has functional IPV4 and IPV6

Well, it still behaves oddly on the ip6-localhost case:

> connect(3, {sa_family=AF_INET6, sin6_port=htons(4101), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = -1 ETIMEDOUT (Connection timed out)

That's really not supposed to time out, and rather just immediately return a "connection refused". Do you have some firewall rules on the lo interface? I'm surprised that this doesn't pose troubles to other system-/session-wide daemons.