STINNER Victor added the comment:
It's easy to reproduce the issue on Linux:
diff --git a/Lib/test/test_asyncio/test_events.py
b/Lib/test/test_asyncio/test_events.py
index 11cd950df1..df4c2b9849 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -3
New submission from STINNER Victor :
AMD64 FreeBSD 10.x Shared 3.7:
http://buildbot.python.org/all/#/builders/124/builds/410
...
test_remove_fds_after_closing
(test.test_asyncio.test_events.KqueueEventLoopTests) ... ok
test_run_in_executor (test.test_asyncio.test_events.KqueueEventLoopTests) .