`TextChoices` subclasses declared inside a class cause "Unable to resolve type of choices property" error

[youtux]

Bug report

What's wrong

Having an enum that extends TextChoices declared inside another class (e.g. a model), results in the following error when running mypy:

file.py: error: Unable to resolve type of choices property  [misc]

Here's an example of such definition:

class MyModel:
    class MyEnum(models.TextChoices):
        foo = "foo", "Foo"
        bar = "bar", "Bar"

a = MyEnum.foo

Running mypy against that:

file.py:9: error: Unable to resolve type of choices property  [misc]

How is that should be

No error should happen.

System information

• OS:
• python version: 3.12.9
• django version: 5.1.8
• mypy version: 1.13.0
• django-stubs version: 5.2.0
• django-stubs-ext version: 5.2.0

[sobolevn]

cc @ngnpope

[ngnpope]

Thanks for the heads-up. Will look into it.

[ngnpope]

@youtux Could you try installing from the master branch? I think this should be fixed by #2646.

[youtux]

the master branch @ e566001 seems to be failing for me (both on mypy 1.13.0 and 1.15.0):

$ mypy file.py --show-traceback
.../lib/python3.12/site-packages/django-stubs/http/request.pyi:56: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 1.15.0
Traceback (most recent call last):
  File "mypy/semanal.py", line 7240, in accept
  File "mypy/nodes.py", line 1345, in accept
  File "mypy/semanal.py", line 3206, in visit_assignment_stmt
  File "mypy/semanal.py", line 3733, in process_type_annotation
  File "mypy/semanal.py", line 6894, in defer
AssertionError: Must not defer during final iteration
.../lib/python3.12/site-packages/django-stubs/http/request.pyi:56: : note: use --pdb to drop into pdb

[youtux]

I managed to run dmypy instead with the master branch, but unfortunately I get a new error:

$ dmypy run
 dmypy run
Restarting: plugins changed
Daemon stopped
Daemon started
...: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 1.13.0
...
Daemon crashed!
Traceback (most recent call last):
  File "mypy/dmypy_server.py", line 236, in serve
  File "mypy/dmypy_server.py", line 285, in run_command
  File "mypy/dmypy_server.py", line 353, in cmd_run
  File "mypy/dmypy_server.py", line 427, in check
  File "mypy/dmypy_server.py", line 466, in initialize_fine_grained
  File "mypy/build.py", line 194, in build
  File "mypy/build.py", line 269, in _build
  File "mypy/build.py", line 2935, in dispatch
  File "mypy/build.py", line 3333, in process_graph
  File "mypy/build.py", line 3434, in process_stale_scc
  File "mypy/build.py", line 2304, in type_check_first_pass
  File "mypy/checker.py", line 483, in check_first_pass
  File "mypy/checker.py", line 594, in accept
  File "mypy/errors.py", line 1269, in report_internal_error
  File "mypy/checker.py", line 592, in accept
  File "mypy/nodes.py", line 1183, in accept
  File "mypy/checker.py", line 2420, in visit_class_def
  File "mypy/checker.py", line 594, in accept
  File "mypy/errors.py", line 1269, in report_internal_error
  File "mypy/checker.py", line 592, in accept
  File "mypy/nodes.py", line 1264, in accept
  File "mypy/checker.py", line 2886, in visit_block
  File "mypy/checker.py", line 594, in accept
  File "mypy/errors.py", line 1269, in report_internal_error
  File "mypy/checker.py", line 592, in accept
  File "mypy/nodes.py", line 1351, in accept
  File "mypy/checker.py", line 2934, in visit_assignment_stmt
  File "mypy/checker.py", line 3112, in check_assignment
  File "mypy/checker.py", line 4271, in check_simple_assignment
  File "mypy/checkexpr.py", line 5850, in accept
  File "mypy/errors.py", line 1269, in report_internal_error
  File "mypy/checkexpr.py", line 5848, in accept
  File "mypy/nodes.py", line 1969, in accept
  File "mypy/checkexpr.py", line 480, in visit_call_expr
  File "mypy/checkexpr.py", line 614, in visit_call_expr_inner
  File "mypy/checkexpr.py", line 1471, in check_call_expr_with_callee_type
  File "mypy/checkexpr.py", line 1565, in check_call
  File "mypy/checkexpr.py", line 1750, in check_callable_call
  File "mypy/checkexpr.py", line 2066, in infer_function_type_arguments
  File "mypy/checkexpr.py", line 1953, in infer_arg_types_in_context
  File "mypy/checkexpr.py", line 5850, in accept
  File "mypy/errors.py", line 1269, in report_internal_error
  File "mypy/checkexpr.py", line 5848, in accept
  File "mypy/nodes.py", line 1893, in accept
  File "mypy/checkexpr.py", line 3269, in visit_member_expr
  File "mypy/checkexpr.py", line 3292, in analyze_ordinary_member_access
  File "mypy/checkmember.py", line 206, in analyze_member_access
  File "mypy/checkmember.py", line 232, in _analyze_member_access
  File "mypy/checkmember.py", line 400, in analyze_type_callable_member_access
  File "mypy/checkmember.py", line 225, in _analyze_member_access
  File "mypy/checkmember.py", line 353, in analyze_instance_member_access
  File "mypy/checkmember.py", line 532, in analyze_member_var_access
  File "mypy/checkmember.py", line 832, in analyze_var
  File ".../lib/python3.12/site-packages/mypy_django_plugin/transformers/choices.py", line 194, in transform_into_proper_attr_type
    has_lazy_label = _has_lazy_label(node)
                     ^^^^^^^^^^^^^^^^^^^^^
  File ".../lib/python3.12/site-packages/mypy_django_plugin/transformers/choices.py", line 36, in _has_lazy_label
    for member_name in node.enum_members:
                       ^^^^^^^^^^^^^^^^^
AttributeError: 'TypeInfo' object has no attribute 'enum_members'

[youtux]

I re-run dmypy run again using mypy 1.15.0, and it works now! so it must have been mypy 1.13.0 not being compatible with django stubs @ master

[youtux]

Could you guys release a new version with this fix?

[ngnpope]

the master branch @ e566001 seems to be failing for me (both on mypy 1.13.0 and 1.15.0):

$ mypy file.py --show-traceback
.../lib/python3.12/site-packages/django-stubs/http/request.pyi:56: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 1.15.0
Traceback (most recent call last):
  File "mypy/semanal.py", line 7240, in accept
  File "mypy/nodes.py", line 1345, in accept
  File "mypy/semanal.py", line 3206, in visit_assignment_stmt
  File "mypy/semanal.py", line 3733, in process_type_annotation
  File "mypy/semanal.py", line 6894, in defer
AssertionError: Must not defer during final iteration
.../lib/python3.12/site-packages/django-stubs/http/request.pyi:56: : note: use --pdb to drop into pdb

This one looks like #2461. See also #2479 for another similar error with a different backtrace.

I managed to run dmypy instead with the master branch, but unfortunately I get a new error:

$ dmypy run
 dmypy run
Restarting: plugins changed
Daemon stopped
Daemon started
...: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 1.13.0
...
Daemon crashed!
Traceback (most recent call last):
  ...
  File ".../lib/python3.12/site-packages/mypy_django_plugin/transformers/choices.py", line 194, in transform_into_proper_attr_type
    has_lazy_label = _has_lazy_label(node)
                     ^^^^^^^^^^^^^^^^^^^^^
  File ".../lib/python3.12/site-packages/mypy_django_plugin/transformers/choices.py", line 36, in _has_lazy_label
    for member_name in node.enum_members:
                       ^^^^^^^^^^^^^^^^^
AttributeError: 'TypeInfo' object has no attribute 'enum_members'

Argh. This is unfortunate. TypeInfo.enum_members was introduced in mypy 1.14, but we have 1.13 as the minimum. This was used as part of the fix in #2646. It looks like it was added in python/mypy@58f7628. We can probably extract the bit we need to keep supporting 1.13.

Could you guys release a new version with this fix?

Once the above is fixed, then I guess we can ask @sobolevn for a release.

[ngnpope]

We can probably extract the bit we need to keep supporting 1.13.

Fix is here: #2669

Edit: The fix has been merged.

[ngnpope]

I think this one can be closed now.

[youtux]

yes, thank you all.

Any ETA for the release?

[bmrobin]

@ngnpope is there a plan to do a 5.2.1 release soon? this and a few other PRs that have merged would be beneficial 🙏