[Python-Dev] Request for CPython 3.5.3 release

[Yury Selivanov]

Long story short, I've discovered that asyncio is broken in 3.5.2.
Specifically, there is a callbacks race in `loop.sock_connect` which
can make subsequent `loop.sock_sendall` calls to hang forever.  This
thing is very tricky and hard to detect and debug; I had to spend a
few hours investigating what's going on with a failing unittest in
uvloop (asyncio-compatible event loop).  I can only imagine how hard
it would be to understand what's going on in a larger codebase.

For those who is interested, here's a PR for asyncio repo:
https://github.com/python/asyncio/pull/366  It explains the bug in
detail and there has a proposed patch to fix the problem.

Larry and the release team: would it be possible to make an
"emergency" 3.5.3 release?

Going forward, we need to increase the number of functional tests for
asyncio, as most of the current tests use mocks. I'm going to port all
functional tests from uvloop to asyncio as a start.

Yury