False SAWarning on second pickle round-trip of an ORM instance with a per-instance lazy loader #13574

    def __getstate__(self):
        if self.extra_criteria is not None:
            util.warn(
                "Can't reliably serialize a lazyload() option that "
                "contains additional criteria; please use eager loading "
                "for this case"
            )
        return {
            "key": self.key,
            "strategy_key": self.strategy_key,
            "loadopt": self.loadopt,
            "extra_criteria": (),
        }

import pickle
import warnings

from sqlalchemy import ForeignKey, create_engine, inspect, select
from sqlalchemy.exc import SAWarning
from sqlalchemy.orm import (
    DeclarativeBase,
    Mapped,
    Session,
    mapped_column,
    raiseload,
    relationship,
)


class Base(DeclarativeBase):
    pass


class Parent(Base):
    __tablename__ = "parent"

    id: Mapped[int] = mapped_column(primary_key=True)
    children: Mapped[list["Child"]] = relationship()


class Child(Base):
    __tablename__ = "child"

    id: Mapped[int] = mapped_column(primary_key=True)
    parent_id: Mapped[int] = mapped_column(ForeignKey("parent.id"))


engine = create_engine("sqlite://")
Base.metadata.create_all(engine)

with Session(engine) as session:
    session.add(Parent(children=[Child()]))
    session.commit()

with Session(engine) as session:
    parent = session.scalar(select(Parent).options(raiseload("*")))
    print("before:", inspect(parent).callables["children"].extra_criteria)
    payload = pickle.dumps(parent)

parent = pickle.loads(payload)
print("after unpickle:", inspect(parent).callables["children"].extra_criteria)

with warnings.catch_warnings(record=True) as caught:
    warnings.simplefilter("always", SAWarning)
    pickle.dumps(parent)

print("warnings:", [str(w.message) for w in caught])