LocalProxy and Flask-SQLAlchemy don't play nicely together

gistfile1.py

from flask import Flask, Response
from flask.ext.sqlalchemy import SQLAlchemy
from werkzeug.local import LocalProxy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/test.db'
app.config["SQLALCHEMY_ECHO"] = True

db = SQLAlchemy(app)

def get_current_friend():
	return Friend.query.filter_by(name="fred").first()

current_name = LocalProxy(lambda: "bob")
current_friend = LocalProxy(get_current_friend)

class Person(db.Model):
	id = db.Column(db.Integer, primary_key=True)
	name = db.Column(db.String)

	friend = db.relationship('Friend', uselist=False)

class Friend(db.Model):
	id = db.Column(db.ForeignKey('person.id'), primary_key=True)
	name = db.Column(db.String)

@app.route('/')
def test():
	# setup
	friend = Friend(name="fred")
	person = Person(name="bob", friend=friend)
	db.session.add(person)
	db.session.commit()

	# make sure to evaluate it early
	print current_friend.name

	result = []
	result.append("== Using a string LocalProxy but it thinks it's the wrong type")
	try:
		person = Person.query.filter_by(name=current_name).first()
	except Exception, error:
		result.append(str(error))

	result.append("== Using a model LocalProxy but it thinks it's None")
	try:
		person = Person.query.filter_by(friend=current_friend).first()
	except Exception, error:
		result.append(str(error))

	result.append("== Creating a model with a string LocalProxy.  Same problem.")
	new_person = Person(name=current_name)
	db.session.add(new_person)
	try:
		db.session.commit()
	except Exception, error:
		db.session.rollback()
		result.append(str(error))

	result.append("== Uh oh, that rollback destroyed my LocalProxy, so I can't even demonstrate the last one.")
	new_person = Person(name="joe", friend=current_friend)
	try:
		db.session.add(new_person)
	except Exception, error:
		result.append(str(error))		

	return Response("\n".join(result), content_type="text/plain")

if __name__ == "__main__":
	db.create_all()
	app.run(debug=True)