Closed
Description
Crash Report
mypy crash with message:
Internal error: must never apply partial type
Traceback
main.py:19: 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: 1.16.0
Traceback (most recent call last):
File "mypy/checkexpr.py", line 5926, in accept
File "mypy/nodes.py", line 2018, in accept
File "mypy/checkexpr.py", line 488, in visit_call_expr
File "mypy/checkexpr.py", line 622, in visit_call_expr_inner
File "mypy/checkexpr.py", line 1478, in check_call_expr_with_callee_type
File "mypy/checkexpr.py", line 1591, in check_call
File "mypy/checkexpr.py", line 2724, in check_overload_call
File "mypy/checkexpr.py", line 2885, in infer_overload_return_type
File "mypy/checkexpr.py", line 1580, in check_call
File "mypy/checkexpr.py", line 1752, in check_callable_call
File "mypy/checkexpr.py", line 2054, in infer_function_type_arguments_using_context
File "mypy/checkexpr.py", line 3260, in apply_generic_arguments
File "mypy/applytype.py", line 112, in apply_generic_arguments
AssertionError: Internal error: must never apply partial type
main.py:19: : note: use --pdb to drop into pdb
To Reproduce
main.py:
from typing import overload, TypeVar, Optional, Protocol
T = TypeVar('T')
class DbManager(Protocol):
@overload
def get(self, key: str) -> Optional[T]:
pass
@overload
def get(self, key: str, default: T) -> T:
pass
class Foo:
def __init__(self, db: DbManager, bar: bool):
if bar:
self.qux = db.get('qux')
else:
self.qux = {}
run mypy:
mypy --show-traceback main.py
Your Environment
- Mypy version used: 1.16.0
- Mypy command-line flags:
- Mypy configuration options from
mypy.ini(and other config files): - Python version used: 3.11.1
- Operating system and version: Ubuntu 20.04.6 LTS
with mypy 1.15.0, I got error:
main.py:21: error: Need type annotation for "qux" (hint: "qux: dict[<type>, <type>] = ...") [var-annotated]
Found 1 error in 1 file (checked 1 source file)
But with mypy 1.16.0, I got error:
main.py:19: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
If this issue continues with mypy master, please report a bug at https://github.com/python/mypy/issues
version: 1.16.0
main.py:19: : note: please use --show-traceback to print a traceback when reporting a bug