部署到ML引擎时发生ClipbyValue错误

当我试图将keras模型部署到ml引擎时

$ gcloud ml-engine versions create v2 --model=plantDisease01 --origin=gs://${BUCKET_NAME}/
plantDisease01 --runtime-version=1.4                                                       
Creating version (this might take a few minutes)......failed.                              ERROR: (gcloud.ml-engine.versions.create) Bad model detected with error:  "Failed to load model: Loading servable: {name: default version: 1} failed: Not found: Op type not registere
d 'ClipByValue' in binary running on localhost. Make sure the Op and Kernel are registered
in the binary running in this process.\n\n (Error code: 0)"
FAIL

我的储藏室看起来像

$ gsutil ls gs://keras-class-191806/plantDisease01/export                      [23:29:38]
gs://keras-class-191806/plantDisease01/export/
gs://keras-class-191806/plantDisease01/export/saved_model.pb

我用这种方法构建了协议缓冲区版本 https://stackoverflow.com/a/44232441/630752