That's unexpected. Do you get a "connection refused" error or something else?

No, it's as if the socket is not even listening to the client it appears. Same behavior as if the server isn't running at all.

Can you try to setLogLevel(LogLevel.Trace) and put the log on pastebin or similar? I'll take a look.

Did that but vibe doesn't seem to write anything at all to the log... if I add a logDebug() message it goes there, but my listenTcp/runEventLoop calls don't appear to log anything. I stepped through them and indeed they don't seem to have any logging calls in the libevent backend?