RK3399Pro入门教程（4）从Tensorflow.Keras到RKNN

rknn读取pb模型失败 按照教程流程得到pb模型后 转换过程中rknn.load_tensorflow = -1，读取失败使得进程被exit（-1），
tf=1.14
rknn=1.6
os=debian10
python=3.7
报错信息：
--> Loading model
I Start importing tensorflow...
E Catch exception when loading tensorflow model: /home/toybrick/codes/model.pb!
E Traceback (most recent call last):
E   File "rknn/api/rknn_base.py", line 209, in rknn.api.rknn_base.RKNNBase.load_tensorflow
E   File "rknn/base/RKNNlib/RK_nn.py", line 47, in rknn.base.RKNNlib.RK_nn.RKnn.load_tensorflow
E   File "rknn/base/RKNNlib/app/importer/import_tensorflow.py", line 58, in rknn.base.RKNNlib.app.importer.import_tensorflow.Importensorflow.run
E   File "rknn/base/RKNNlib/app/importer/import_tensorflow.py", line 53, in rknn.base.RKNNlib.app.importer.import_tensorflow.Importensorflow.import_tf_ruler_module
E   File "/home/toybrick/.local/lib/python3.7/site-packages/rknn/base/RKNNlib/converter/tfruler/__init__.py", line 2, in <module>
E     from .tf_ruler_generate import r_add_n_template, r_concatv2_template, r_split_template
E ImportError: cannot import name 'r_add_n_template' from 'tfruler.tf_ruler_generate' (/home/toybrick/.local/lib/python3.7/site-packages/rknn/base/RKNNlib/converter/tfruler/tf_ruler_generate.cpython-37m-aarch64-linux-gnu.so)
Load mtcnn failed! Ret = -1