py 1.5 breaks freezegun on Windows

[Kwpolska]

My AppVeyor (Windows) tests recently started failing with this:

================================== FAILURES ===================================
________________________ TestScheduling.test_get_date _________________________
c:\python36\lib\site-packages\freezegun\api.py:494: in wrapper
    with self:
c:\python36\lib\site-packages\freezegun\api.py:365: in __enter__
    return self.start()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <freezegun.api._freeze_time object at 0x052C2270>

    def start(self):
        if self.tick:
            time_to_freeze = TickingDateTimeFactory(self.time_to_freeze, real_datetime.now())
        else:
            time_to_freeze = FrozenDateTimeFactory(self.time_to_freeze)
    
        # Change the modules
        datetime.datetime = FakeDatetime
        datetime.date = FakeDate
        fake_time = FakeTime(time_to_freeze, time.time)
        fake_localtime = FakeLocalTime(time_to_freeze, time.localtime)
        fake_gmtime = FakeGMTTime(time_to_freeze, time.gmtime)
        fake_strftime = FakeStrfTime(time_to_freeze, time.strftime)
        time.time = fake_time
        time.localtime = fake_localtime
        time.gmtime = fake_gmtime
        time.strftime = fake_strftime
        uuid._uuid_generate_time = None
        uuid._UuidCreate = None
    
        copyreg.dispatch_table[real_datetime] = pickle_fake_datetime
        copyreg.dispatch_table[real_date] = pickle_fake_date
    
        # Change any place where the module had already been imported
        to_patch = [
            ('real_date', real_date, 'FakeDate', FakeDate),
            ('real_datetime', real_datetime, 'FakeDatetime', FakeDatetime),
            ('real_gmtime', real_gmtime, 'FakeGMTTime', fake_gmtime),
            ('real_localtime', real_localtime, 'FakeLocalTime', fake_localtime),
            ('real_strftime', real_strftime, 'FakeStrfTime', fake_strftime),
            ('real_time', real_time, 'FakeTime', fake_time),
        ]
        real_names = tuple(real_name for real_name, real, fake_name, fake in to_patch)
        self.fake_names = tuple(fake_name for real_name, real, fake_name, fake in to_patch)
        self.reals = dict((id(fake), real) for real_name, real, fake_name, fake in to_patch)
        fakes = dict((id(real), fake) for real_name, real, fake_name, fake in to_patch)
        add_change = self.undo_changes.append
    
        # Save the current loaded modules
        self.modules_at_start = set(sys.modules.keys())
    
        with warnings.catch_warnings():
            warnings.filterwarnings('ignore')
    
            for mod_name, module in list(sys.modules.items()):
                if mod_name is None or module is None:
                    continue
                elif mod_name.startswith(self.ignore):
                    continue
                elif (not hasattr(module, "__name__") or module.__name__ in ('datetime', 'time')):
                    continue
>               for module_attribute in dir(module):
E               ModuleNotFoundError: No module named 'syslog'

c:\python36\lib\site-packages\freezegun\api.py:421: ModuleNotFoundError
================ 1 failed, 202 passed in -133582692.64 seconds ================

I investigated a little, and I found out that this appears only with py 1.5.x. Rolling back to py==1.4.34 fixes the issue. Is this a bug in py or freezegun?

(see also: spulec/freezegun#214)

[nicoddemus]

@Kwpolska unfortunately this is a bug in py, see #170 .

I will work on a fix ASAP.

[gvanrossum]

It's not just freezegun. It happened to the mypy project too, and we fixed it the same way. There's an AppVeyor support ticket but honestly I think the problem is here, in the py.log module -- it now unconditionally imports syslog which AFAICT is UNIX only -- it's in the doc section labeled "Unix specific services".

[nicoddemus]

@gvanrossum your assessment is correct. At the time some refactoring was done, there was no proper Windows CI and that import escaped unnoticed.

[gvanrossum]

Thanks -- please ping this ticket when a release with the fix is available.

[nicoddemus]

@gvanrossum and @Kwpolska, 1.5.2 has been released with the fix, thanks again for the reports! 👍

[Kwpolska]

My build passes, thanks!