INTERNAL ERROR when importing into a class

[Kyuuhachi]

Crash Report

It seems that mypy doesn't like from x import y statements inside classes. While maybe unusual, from dataclasses import replace is quite handy.

Traceback

Running as mypy --show-traceback a.py, on commit 8e909e4.

a.py:4: error: INTERNAL ERROR -- Please try using mypy master on Github:
https://mypy.rtfd.io/en/latest/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 0.812
Traceback (most recent call last):
  File "mypy/checkexpr.py", line 3898, in accept
  File "mypy/nodes.py", line 1507, in accept
  File "mypy/checkexpr.py", line 2025, in visit_member_expr
  File "mypy/checkexpr.py", line 2043, in analyze_ordinary_member_access
  File "mypy/checkmember.py", line 126, in analyze_member_access
  File "mypy/checkmember.py", line 143, in _analyze_member_access
  File "mypy/checkmember.py", line 219, in analyze_instance_member_access
  File "mypy/maptype.py", line 20, in map_instance_to_supertype
AttributeError: attribute 'type_vars' of 'TypeInfo' undefined
a.py:4: : note: use --pdb to drop into pdb

To Reproduce

a.py:

class A:
	from b import foo

print(A().foo())  # ← INTERNAL ERROR here

b.py:

def foo(self):
	return ""

Your Environment

• Mypy version used: 8e909e4
• Mypy command-line flags: mypy --show-traceback a.py
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: 3.9.5
• Operating system and version: Arch

[hauntsaninja]

Thanks, fixed in #12023 and #12199