import statements under a parametrised protocol results in a crash

[XM-Helico]

Crash Report & Reproduction

The following snippet will cause a crash:

import typing as tp

T = tp.TypeVar("T")

class Proto(tp.Protocol[T]):
    import urllib

**Traceback**
<file>: 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: 1.1.1
Traceback (most recent call last):
  File "mypy/checker.py", line 582, in accept
  File "mypy/nodes.py", line 1123, in accept
  File "mypy/checker.py", line 2219, in visit_class_def
  File "mypy/checker.py", line 2403, in check_protocol_variance
  File "mypy/subtypes.py", line 177, in is_subtype
  File "mypy/subtypes.py", line 336, in _is_subtype
  File "mypy/types.py", line 1355, in accept
  File "mypy/subtypes.py", line 603, in visit_instance
  File "mypy/subtypes.py", line 1041, in is_protocol_implementation
AssertionError: 

No issues happen when the protocol isn't parameterised.

Your Environment

• Mypy version used: 1.1.1 and master (mypy-play.net)
• Mypy command-line flags: None
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: 3.10 and 3.11

[tyralla]

I guess the imported module is not supposed to be an "official" member of the protocol, should it? (And that PEP 544 does not mention such cases?)

If so, one could silently ignore this member, which should be little effort.

[ilevkivskyi]

Yeah, I am going to simply ignore all imports.