I wonder if the fix shouldn't apply to all callers of _create_fn()? I know init is the only one that (currently) has annotations, but in general I wish the generated functions looked more like handwritten ones to various introspection tools.

I think there's no harm in doing that. I've updated the PR. It's a bit more invasive now, but the benefit is that we always use the same mechanism (a closure) to inject objects into generated code.

BTW this looks like a relatively safe change for 3.7.1, but it's Eric's call.

I'll try and look at this today. Thanks, @1st1 and @gvanrossum for the code and reviews.

According to https://discuss.python.org/t/3-7-1-and-3-6-7-release-update/184 there's still couple of days to get this into 3.7.1. @ericvsmith do you have time for a review?

FWIW we can just merge the 39006fb commit to 3.7 which does the trick in the most minimal way.

Unfortunately I'm out of town until 2018-10-10 with limited internet access until then. I won't be able to do a decent review until then.

Hi Eric, Python 3.7.2rc1 has been released but this PR is still not merged. Is it possible to somehow unblock it?

I apologize for being tied up with a client on end-of-year work. I don't see how this could get in to 3.7.2, but I'm planning on looking at it in January.

It looks like https://bugs.python.org/issue37948 will be also fixed by this PR.

It looks like https://bugs.python.org/issue37948 will be also fixed by this PR.

It won't, I just tested with https://github.com/1st1/cpython/tree/fix_dc_introspect

It won't, I just tested with https://github.com/1st1/cpython/tree/fix_dc_introspect

@a-recknagel : Could you post your test code and the results? Thanks.

@ericvsmith Sure. python was built from e38de43, and I ran

>>> import dataclasses
>>> import typing
>>> A = dataclasses.make_dataclass('A', ['var'])
>>> typing.get_type_hints(A)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/arne/pythons/python_dc_fix/lib/python3.8/typing.py", line 972, in get_type_hints
    value = _eval_type(value, base_globals, localns)
  File "/home/arne/pythons/python_dc_fix/lib/python3.8/typing.py", line 259, in _eval_type
    return t._evaluate(globalns, localns)
  File "/home/arne/pythons/python_dc_fix/lib/python3.8/typing.py", line 463, in _evaluate
    eval(self.__forward_code__, globalns, localns),
  File "<string>", line 1, in <module>
NameError: name 'typing' is not defined

Which is the same behavior as on the current master.

@ambv: Please replace # with GH- in the commit message next time. Thanks!

Thanks @1st1 for the PR, and @ambv for merging it 🌮🎉.. I'm working now to backport this PR to: 3.8.
🐍🍒⛏🤖

Thanks @1st1 for the PR, and @ambv for merging it 🌮🎉.. I'm working now to backport this PR to: 3.7.
🐍🍒⛏🤖 I'm not a witch! I'm not a witch!

GH-17531 is a backport of this pull request to the 3.8 branch.

GH-17532 is a backport of this pull request to the 3.7 branch.