scikeras: Sequential model doesn't have outputs

Shouldn’t this code work?

from sklearn.datasets import make_classification
from scikeras.wrappers import KerasClassifier
import tensorflow as tf

def model():
    model = tf.keras.Sequential()
    model.add(tf.keras.layers.Dense(8))
    model.add(tf.keras.layers.Dense(1))
    return model

X, y = make_classification(n_features=8)
est = KerasClassifier(model=model, loss="sparse_categorical_crossentropy")
est.fit(X, y=y)

This throws a ValueError: object of type NoneType [self.model_.outputs] has no len().

Full traceback

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
~/Downloads/_junk2.py in <module>
     11 X, y = make_classification(n_features=8)
     12 est = KerasClassifier(model=model, loss="sparse_categorical_crossentropy")
---> 13 est.fit(X, y=y)

~/anaconda3/envs/scikeras/lib/python3.7/site-packages/scikeras/wrappers.py in fit(self, X, y, sample_weight, **kwargs)
   1375             sample_weight = 1 if sample_weight is None else sample_weight
   1376             sample_weight *= compute_sample_weight(class_weight=self.class_weight, y=y)
-> 1377         super().fit(X=X, y=y, sample_weight=sample_weight, **kwargs)
   1378         return self
   1379

~/anaconda3/envs/scikeras/lib/python3.7/site-packages/scikeras/wrappers.py in fit(self, X, y, sample_weight, **kwargs)
    739             epochs=getattr(self, "fit__epochs", self.epochs),
    740             initial_epoch=0,
--> 741             **kwargs,
    742         )
    743

~/anaconda3/envs/scikeras/lib/python3.7/site-packages/scikeras/wrappers.py in _fit(self, X, y, sample_weight, warm_start, epochs, initial_epoch, **kwargs)
    855         X = self.feature_encoder_.transform(X)
    856
--> 857         self._check_model_compatibility(y)
    858
    859         self._fit_keras_model(

~/anaconda3/envs/scikeras/lib/python3.7/site-packages/scikeras/wrappers.py in _check_model_compatibility(self, y)
    541             # we recognize the attribute but do not force it to be
    542             # generated
--> 543             if self.n_outputs_expected_ != len(self.model_.outputs):
    544                 raise ValueError(
    545                     "Detected a Keras model input of size"

TypeError: object of type 'NoneType' has no len()

scikeras: Sequential model doesn't have outputs

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