It seems there was a deprecation warning added in ad4ed872415d00fcdfaa52a08108ec752b115000 that causes error when test_asyncio.test_pep492.StreamReaderTests.test_readline is ran with -Werror.


➜  cpython git:(master) ./python.exe -Werror -m unittest -v test.test_asyncio.test_pep492.StreamReaderTests.test_readline
test_readline (test.test_asyncio.test_pep492.StreamReaderTests) ... ERROR

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ERROR: test_readline (test.test_asyncio.test_pep492.StreamReaderTests)
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Traceback (most recent call last):
  File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/test/test_asyncio/test_pep492.py", line 97, in test_readline
    stream = asyncio.StreamReader(loop=self.loop)
  File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/asyncio/streams.py", line 446, in __init__
    warnings.warn(f"{self.__class__} should be instaniated "
DeprecationWarning: <class 'asyncio.streams.StreamReader'> should be instaniated by asyncio internals only, please avoid its creation from user code

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Ran 1 test in 0.003s

FAILED (errors=1)

# Before commit

➜  cpython git:(master) git checkout ad4ed872415d00fcdfaa52a08108ec752b115000~1 Lib/asyncio
➜  cpython git:(master) ✗ ./python.exe -Werror -m unittest -v test.test_asyncio.test_pep492.StreamReaderTests.test_readline
test_readline (test.test_asyncio.test_pep492.StreamReaderTests) ... ok

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Ran 1 test in 0.004s

OK