Python completely freezes when uses Generator(Iterable) and itertools.repeat

[levsh]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

Hi!
Python freezes and not responding on Ctrl^C
How to fix this?
Thank you

Example Code

import itertools
from collections.abc import Generator, Iterable
from pydantic import BaseModel

class M(BaseModel):
    x: list[int] | Generator[int]
    # x: list[int] | Iterable[int]  # same result


m = M(x=[1])  # -> ok
m = M(x=itertools.repeat(5))  # -> freeze

Python, Pydantic & OS Version

pydantic version: 2.7.0
        pydantic-core version: 2.18.1
          pydantic-core build: profile=release pgo=false
                 install path: /Users/.../.pyenv/versions/3.11.5/lib/python3.11/site-packages/pydantic
               python version: 3.11.5 (main, Sep 16 2023, 09:45:16) [Clang 12.0.5 (clang-1205.0.22.11)]
                     platform: macOS-11.7.10-x86_64-i386-64bit
             related packages: typing_extensions-4.11.0 typing_extensions-4.8.0 pyright-1.1.332 pydantic-settings-2.2.1
                       commit: unknown

[levsh]

And Any with model_dump_json not works also

import itertools
from typing import Any
from pydantic import BaseModel

class M(BaseModel):
    x: Any

m = M(x=[1])
m.model_dump()  # ok
m.model_dump_json()  # ok

m = M(x=itertools.repeat(5))
m.model_dump()  # ok
m.model_dump_json()  # -> freeze

[Viicos]

repeat(5) is an infinite iterator, what behavior are you expecting when doing m = M(x=itertools.repeat(5))? Pydantic could implement an iteration limit to avoid infinite loops but this is probably the responsibility of the developer.

[levsh]

@Viicos i try to define field that accept both list[int] and itertools.repeat and .model_dump returns original value without modification or unwraping infinity itertools.repeat
This example works(not freezing)

class M(BaseModel):
    x: Iterable[int] | list[int]

but for M(x=[5]).model_dump() returns SerializationIterator

{'x': SerializationIterator(index=0, iterator=ValidatorIterator(index=0, schema=Some(Int(IntValidator { strict: false }))))}

instead of [5]

Alternative version works for list[int] but freezing for itertools.repeat

class M(BaseModel):
    x: list[int] | Iterable[int]

And it would be perfect to get exception from Pydantic instead of freeze (if it is possible)

Thank you.