> Would you please be more specific on test_signal?

Please try to compile Python 3.4 with the attached cygwin_si_band.patch applied, and then run test_signal. I would like to know if all tests pass, and if not, which tests are failing. I also would like to know if test_sigwaitinfo() runs on Cygwin. I'm not sure that signal.alarm(1) is available on Windows, whereas test_sigwaitinfo() uses this function.

Or you can test manually sigwaitinfo(). Example on Windows using SIGINT and CTRL+c to send a signal:

>>> import signal
>>> info = signal.sigwaitinfo({signal.SIGINT})
^C
>>> info
signal.struct_siginfo(si_signo=2, si_code=128, si_errno=0, si_pid=0, si_uid=0, si_status=3, si_band=0)

I don't know how to test sigwaitinfo() on Windows.