On a fresh checkout, I'm getting two test failures: $ ./configure && make $ ./python.exe -m test.regrtest -v test_asyncore [snip] ====================================================================== FAIL: test_handle_expt (test.test_asyncore.TestAPI_UseIPv4Poll) ---------------------------------------------------------------------- Traceback (most recent call last): File "/Users/raymond/cleancpython/Lib/test/test_asyncore.py", line 674, in test_handle_expt self.loop_waiting_for_flag(client) File "/Users/raymond/cleancpython/Lib/test/test_asyncore.py", line 514, in loop_waiting_for_flag self.fail("flag not set") AssertionError: flag not set ====================================================================== FAIL: test_handle_expt (test.test_asyncore.TestAPI_UseIPv6Poll) ---------------------------------------------------------------------- Traceback (most recent call last): File "/Users/raymond/cleancpython/Lib/test/test_asyncore.py", line 674, in test_handle_expt self.loop_waiting_for_flag(client) File "/Users/raymond/cleancpython/Lib/test/test_asyncore.py", line 514, in loop_waiting_for_flag self.fail("flag not set") AssertionError: flag not set ---------------------------------------------------------------------- Ran 101 tests in 20.506s FAILED (failures=2, skipped=6) test test_asyncore failed test_asyncore failed 1 test failed: test_asyncore $ ./python.exe -m test.regrtest -v test_eintr [snip] ====================================================================== FAIL: test_poll (__main__.SelectEINTRTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/Users/raymond/cleancpython/Lib/test/eintrdata/eintr_tester.py", line 446, in test_poll self.assertGreaterEqual(dt, self.sleep_time) AssertionError: 9.176997991744429e-06 not greater than or equal to 0.2 ---------------------------------------------------------------------- Ran 22 tests in 5.288s FAILED (failures=1, skipped=5) --- stderr: --- Traceback (most recent call last): File "/Users/raymond/cleancpython/Lib/test/eintrdata/eintr_tester.py", line 492, in <module> test_main() File "/Users/raymond/cleancpython/Lib/test/eintrdata/eintr_tester.py", line 488, in test_main SelectEINTRTest) File "/Users/raymond/cleancpython/Lib/test/support/__init__.py", line 1849, in run_unittest _run_suite(suite) File "/Users/raymond/cleancpython/Lib/test/support/__init__.py", line 1824, in _run_suite raise TestFailed(err) test.support.TestFailed: Traceback (most recent call last): File "/Users/raymond/cleancpython/Lib/test/eintrdata/eintr_tester.py", line 446, in test_poll self.assertGreaterEqual(dt, self.sleep_time) AssertionError: 9.176997991744429e-06 not greater than or equal to 0.2 --- ---------------------------------------------------------------------- Ran 1 test in 5.424s FAILED (failures=1) test test_eintr failed test_eintr failed 1 test failed: test_eintr Total duration: 5 sec Tests result: FAILURE

See https://daniel.haxx.se/blog/2016/10/11/poll-on-mac-10-12-is-broken/ C function poll() seems to be broken on Sierra.

Try to modify pyconfig.h to define HAVE_BROKEN_POLL. It should work around the bug. configure.ac contains a test for HAVE_BROKEN_POLL. We need another test for poll() being broken differently. Note: asyncio doesn't seem to be affect because it probably uses the more efficient kqueue by default on OS X.

This is a duplicate of Issue28087.