Oleg

btw I've created golang implementation of asap smoothing https://github.com/errx/go-asap

Same problem. Steps to reproduce ``` host localhost localhost has address 127.0.0.1 localhost has IPv6 address ::1 ``` start listen only ipv4 ```ncat -4 -v -v -l 127.0.0.1``` then try...

If I add and call "wait" function from async psycopg example (http://initd.org/psycopg/docs/advanced.html#asynchronous-support) everything works ok

listening on ::1 and connecting to `localhost`? works

minimal example asyncio.get_event_loop().run_until_complete(aiopg.connect("host=localhost port=12345"))

on state == POLL_WRITE always removing old writer and adding new fixes this problem

I guess the key point to reproduce this issue is to have 127.0.0.1 localhost and ::1 localhost in /etc/hosts (it's set by default in osx and debian for example but...

My hypothesis (based on tcpdump and strace) is that after first failed ipv6 connection socket is closed and than new socket is created with same fd (probably inside libpq? didn't...

I'm sorry but I'm not sure how this flag will help, care to elaborate?

Yes, fd didn't change but I guess this is not always true. I can show strace logs but unfortunately not today