test.test_coroutines.CoroAsyncIOCompatTest.test_asyncio_1() fails with --without-threads, because it imports asyncio module, which is known to not work with --without-threads.
This test should be skipped when import of asyncio fails.

======================================================================
ERROR: test_asyncio_1 (test.test_coroutines.CoroAsyncIOCompatTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/cpython/Lib/test/test_coroutines.py", line 1325, in test_asyncio_1
    import asyncio
  File "/tmp/cpython/Lib/asyncio/__init__.py", line 21, in <module>
    from .base_events import *
  File "/tmp/cpython/Lib/asyncio/base_events.py", line 18, in <module>
    import concurrent.futures
  File "/tmp/cpython/Lib/concurrent/futures/__init__.py", line 8, in <module>
    from concurrent.futures._base import (FIRST_COMPLETED,
  File "/tmp/cpython/Lib/concurrent/futures/_base.py", line 8, in <module>
    import threading
  File "/tmp/cpython/Lib/threading.py", line 4, in <module>
    import _thread
ImportError: No module named '_thread'

----------------------------------------------------------------------

Can you test with this patch?

It works.
A more standard way would be 'self.skipTest(...)' instead of 'raise unittest.SkipTest(...)'.

You also can use special helper: test.support.import_module().

Can one of you produce a proper patch? Then the other can review. Serhiy can commit it.

New changeset d8737b841fcf by Victor Stinner in branch '3.5':
Close #25367: Fix test_coroutines with no thread support
https://hg.python.org/cpython/rev/d8737b841fcf

New changeset d8002372e5df by Victor Stinner in branch 'default':
Merge 3.5 (test_coroutines, issue #25367)
https://hg.python.org/cpython/rev/d8002372e5df

I fixed the issue based on Guido's patch and Serhiy's suggestion.

======================================================================
ERROR: test_asyncio_1 (test.test_coroutines.CoroAsyncIOCompatTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/cpython/Lib/test/test_coroutines.py", line 1351, in test_asyncio_1
    loop = asyncio.new_event_loop()
NameError: name 'asyncio' is not defined

----------------------------------------------------------------------

New changeset 493845d905c5 by Victor Stinner in branch '3.5':
Close #25367: Fix test_coroutines()
https://hg.python.org/cpython/rev/493845d905c5

> NameError: name 'asyncio' is not defined

Oops :-( I also fixed this one, sorry.