thirdparty: remove Python 2-specific selectors2 copy The selectors module was added in Python 3.4. Because we require Python 3.6, it will always be available. Therefore the selectors2 module is not imported. I’ve verified that the selectors2-specific workaround in commandserver.py is not necessary with the selectors module from the standard library. It returns an empty list if timeout was exceeded. The pytype directive was needed to silence the following error: File "/tmp/mercurial-ci/mercurial/worker.py", line 299, in _posixworker: No attribute 'close' on int [attribute-error] In Union[_typeshed.HasFileno, int] File "/tmp/mercurial-ci/mercurial/worker.py", line 299, in _posixworker: No attribute 'close' on _typeshed.HasFileno [attribute-error] In Union[_typeshed.HasFileno, int]