Spotted at https://dev.azure.com/Python/cpython/_build/results?buildId=66387&view=logs&j=d554cd63-f8f4-5b2d-871b-33e4ea76e915&t=5a14d0eb-dbd4-5b80-f5d0-7909f950a1cc&l=1859

test_empty_input (test.test_asyncio.test_subprocess.SubprocessProactorTests) ... ok
test_exec_loop_deprecated (test.test_asyncio.test_subprocess.SubprocessProactorTests) ... ok
test_kill (test.test_asyncio.test_subprocess.SubprocessProactorTests) ... ok
Warning -- Unraisable exception
Warning -- Unraisable exception
Timeout (0:20:00)!
Thread 0x00001eac (most recent call first):
  File "D:\a\1\s\lib\asyncio\windows_events.py", line 779 in _poll
  File "D:\a\1\s\lib\asyncio\windows_events.py", line 430 in select
  File "D:\a\1\s\lib\asyncio\base_events.py", line 1854 in _run_once
  File "D:\a\1\s\lib\asyncio\base_events.py", line 596 in run_forever
  File "D:\a\1\s\lib\asyncio\windows_events.py", line 316 in run_forever
  File "D:\a\1\s\lib\asyncio\base_events.py", line 629 in run_until_complete
  File "D:\a\1\s\lib\test\test_asyncio\test_subprocess.py", line 302 in test_pause_reading
  File "D:\a\1\s\lib\unittest\case.py", line 549 in _callTestMethod
  File "D:\a\1\s\lib\unittest\case.py", line 592 in run
  File "D:\a\1\s\lib\unittest\case.py", line 652 in __call__
  File "D:\a\1\s\lib\unittest\suite.py", line 122 in run
  File "D:\a\1\s\lib\unittest\suite.py", line 84 in __call__
  File "D:\a\1\s\lib\unittest\suite.py", line 122 in run
  File "D:\a\1\s\lib\unittest\suite.py", line 84 in __call__
  File "D:\a\1\s\lib\unittest\suite.py", line 122 in run
  File "D:\a\1\s\lib\unittest\suite.py", line 84 in __call__
  File "D:\a\1\s\lib\unittest\suite.py", line 122 in run
  File "D:\a\1\s\lib\unittest\suite.py", line 84 in __call__
  File "D:\a\1\s\lib\unittest\suite.py", line 122 in run
  File "D:\a\1\s\lib\unittest\suite.py", line 84 in __call__
  File "D:\a\1\s\lib\unittest\runner.py", line 176 in run
  File "D:\a\1\s\lib\test\support\__init__.py", line 975 in _run_suite
  File "D:\a\1\s\lib\test\support\__init__.py", line 1098 in run_unittest
  File "D:\a\1\s\lib\test\libregrtest\runtest.py", line 211 in _test_module
  File "D:\a\1\s\lib\test\libregrtest\runtest.py", line 236 in _runtest_inner2
  File "D:\a\1\s\lib\test\libregrtest\runtest.py", line 272 in _runtest_inner
  File "D:\a\1\s\lib\test\libregrtest\runtest.py", line 155 in _runtest
  File "D:\a\1\s\lib\test\libregrtest\runtest.py", line 195 in runtest
  File "D:\a\1\s\lib\test\libregrtest\main.py", line 319 in rerun_failed_tests
  File "D:\a\1\s\lib\test\libregrtest\main.py", line 696 in _main
  File "D:\a\1\s\lib\test\libregrtest\main.py", line 639 in main
  File "D:\a\1\s\lib\test\libregrtest\main.py", line 717 in main
  File "D:\a\1\s\lib\test\__main__.py", line 2 in <module>
  File "D:\a\1\s\lib\runpy.py", line 87 in _run_code
  File "D:\a\1\s\lib\runpy.py", line 197 in _run_module_as_main
##[error]Cmd.exe exited with code '1'.