TimeoutError when connecting to server

• asyncpg version: 0.20.1, 0.19.0, 0.18.3, 0.17.0, 0.16.0
• PostgreSQL version: 10.6
• Do you use a PostgreSQL SaaS? If so, which? Can you reproduce
  the issue with a local PostgreSQL install?: No SaaS
• Python version: 3.7.3
• Platform: MacOs 10.15.4 / Alpine Linux
• Do you use pgbouncer?: No
• Did you install asyncpg with pip?: Tried both: pip and build from source
• If you built asyncpg locally, which version of Cython did you use?: 0.29.14 for 0.20.1
• Can the issue be reproduced under both asyncio and
  uvloop?: Yes, both with and without uvloop

Hi! I ran into a very strange behaviour of asyncpg. I can connect to a server with Postgresql 10.6 via psql, psycopg2, aoipg, but not asyncpg. The code is very simple:

async def main():
    print('start')
    c = await connect('postgresql://someuser:somepwd@somehost:5433/somedb')
    print('finish')

import asyncio

asyncio.run(main())

and get exception:

  File ".../tst_asyncpg.py", line 12, in <module>
    asyncio.run(main())
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/runners.py", line 43, in run
    return loop.run_until_complete(main)
  File "uvloop/loop.pyx", line 1456, in uvloop.loop.Loop.run_until_complete
  File ".../ceres/tst_asyncpg.py", line 7, in main
    c = await connect('<some dsn>')
  File ".../venv/lib/python3.7/site-packages/asyncpg/connection.py", line 1677, in connect
    max_cacheable_statement_size=max_cacheable_statement_size)
  File ".../venv/lib/python3.7/site-packages/asyncpg/connect_utils.py", line 663, in _connect
    raise last_error
  File ".../venv/lib/python3.7/site-packages/asyncpg/connect_utils.py", line 655, in _connect
    connection_class=connection_class)
  File ".../venv/lib/python3.7/site-packages/asyncpg/connect_utils.py", line 631, in _connect_addr
    await asyncio.wait_for(connected, timeout=timeout)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/tasks.py", line 423, in wait_for
    raise futures.TimeoutError()
concurrent.futures._base.TimeoutError

This exception is raised after 60 seconds. I tired different versions of asyncpg, and the behaviour does not change. Right now i'm building library from source in hope to get some additional debug info. I'm nearly sure, that it is not a network issue (other libraries / utilities go well).
I checked logs on postgresql, and have a 'canceling authentication due to timeout' for every connection attempt. By the way, i have another instance of postgresql on a server (different port), and it works well.

I will appreciate any advice, how to debug this problem. Thanks.

connection.py の接続エントリポイントと connect_utils.py のタイムアウト経路から始め、特に _connect と _connect_addr を確認してください。失敗する asyncpg 接続試行を、認証のキャンセルを示す PostgreSQL のログエントリと比較し、報告されている挙動を、一覧にある asyncpg のバージョンおよび環境全体で確認してください。完了条件は、再現可能な原因、または明確に実行可能な診断を特定することです。