Traceback (most recent call last):


 "balloon.py", line 330, in <module>

model = modellib.MaskRCNN(mode="training", config=config, model_dir=args.logs)


 "/home/ubuntu/examples/research/mask-rcnn/mrcnn/model.py", line 1837, in __init__

self.keras_model = self.build(mode=mode, config=config)


 "/home/ubuntu/examples/research/mask-rcnn/mrcnn/model.py", line 1876, in build

x, K.shape(input_image)[1:3]))(input_gt_boxes)


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/base_layer.py", line 952, in __call__

input_list)


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/base_layer.py", line 1091, in _functional_construction_call

inputs, input_masks, args, kwargs)


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/base_layer.py", line 822, in _keras_tensor_symbolic_call

return self._infer_output_signature(inputs, args, kwargs, input_masks)


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/base_layer.py", line 869, in _infer_output_signature

keras_tensor.keras_tensor_from_tensor, outputs)


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/util/nest.py", line 659, in map_structure

structure[0], [func(*x) for x in entries],


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/util/nest.py", line 659, in <listcomp>

structure[0], [func(*x) for x in entries],


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/keras_tensor.py", line 606, in keras_tensor_from_tensor

out = keras_tensor_cls.from_tensor(tensor)


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/keras/engine/keras_tensor.py", line 205, in from_tensor

type_spec = type_spec_module.type_spec_from_value(tensor)


 "/home/ubuntu/anaconda3/lib/python3.7/site-packages/tensorflow/python/framework/type_spec.py", line 554, in type_spec_from_value

(value, type(value).__name__))
TypeError: Could not build a TypeSpec for <KerasTensor: shape=(None, None, 4) dtype=float32 (created by layer 'tf.math.truediv')> with type KerasTensor

Traceback (most recent call last):


 "/usr/local/bin/pipenv", line 11, in <module>

sys.exit(cli())


 "/usr/local/lib/python3.6/dist-packages/pipenv/vendor/click/core.py", line 722, in __call__

return self.main(*args, **kwargs)


 "/usr/local/lib/python3.6/dist-packages/pipenv/vendor/click/core.py", line 697, in main

rv = self.invoke(ctx)


 "/usr/local/lib/python3.6/dist-packages/pipenv/vendor/click/core.py", line 1066, in invoke

return _process_result(sub_ctx.command.invoke(sub_ctx))


 "/usr/local/lib/python3.6/dist-packages/pipenv/vendor/click/core.py", line 895, in invoke

return ctx.invoke(self.callback, **ctx.params)


 "/usr/local/lib/python3.6/dist-packages/pipenv/vendor/click/core.py", line 535, in invoke

return callback(*args, **kwargs)


 "/usr/local/lib/python3.6/dist-packages/pipenv/cli.py", line 402, in install

selective_upgrade=selective_upgrade,


 "/usr/local/lib/python3.6/dist-packages/pipenv/core.py", line 1932, in do_install

requirements_dir=requirements_directory,


 "/usr/local/lib/python3.6/dist-packages/pipenv/core.py", line 1369, in do_init

verbose=verbose,


 "/usr/local/lib/python3.6/dist-packages/pipenv/core.py", line 1043, in do_lock

allow_global=system,


 "/usr/local/lib/python3.6/dist-packages/pipenv/utils.py", line 420, in venv_resolve_deps

escape_grouped_arguments(which('python', allow_global=allow_global)),


 "/usr/local/lib/python3.6/dist-packages/pipenv/core.py", line 128, in which

p = os.sep.join([location] + ['bin/{0}'.format(command)])
TypeError: sequence item 0: expected str instance, NoneType found
