timezone free datetime.datetime.fromtimestamp returns original datetime.datetime

[jogo]

import datetime
import pickle
import time

import pytz
from freezegun import freeze_time


class Foo:
    def __init__(self):
        self.now = datetime.datetime.fromtimestamp(time.time())

    def __reduce__(self):
        # https://docs.python.org/3/library/pickle.html#object.__reduce__
        return self.now.__reduce__()


with freeze_time():
    dt = datetime.datetime.fromtimestamp(time.time(), tz=pytz.utc)
    print(repr(dt))

    dt = datetime.datetime.fromtimestamp(time.time())
    print(repr(dt))

    pickle.dumps(Foo())

Results in

FakeDatetime(2024, 3, 14, 21, 12, 0, 615787, tzinfo=<UTC>)
datetime.datetime(2024, 3, 14, 21, 12, 0, 615787)
Traceback (most recent call last):
  File "FILE", line 25, in <module>
    pickle.dumps(Foo())
_pickle.PicklingError: Can't pickle <class 'datetime.datetime'>: it's not the same object as datetime.datetime

This sample shows two related issues:

1. freezegun/freezegun/api.py

   Line 377 in 12e54da

   return real_datetime.fromtimestamp(

   returns real_datetime while everything else uses FakeDatetime
2. In some cases real_datetime won't pickle correctly when datetime is patched.

I think this case should be addressed by #475

[bblommers]

Hi @jogo! #475 does indeed fix this, as far as I can tell.

That PR is merged now, so I'll close this one. Thank you for raising this!