mnist-node example: backend.select is not a function

To get help from the community, check out our Google group.

TensorFlow.js version

0.12.4

The example here is not working properly: https://github.com/tensorflow/tfjs-examples/tree/master/mnist-node

When I add yarn followed by node index.js, I get the following error:

(node:199628) UnhandledPromiseRejectionWarning: TypeError: backend.select is not a function at environment_1.ENV.engine.runKernel.$condition (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/ops/logical_ops.js:88:83) at /usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/engine.js:115:26 at Engine.scopedRun (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/engine.js:95:23) at Engine.runKernel (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/engine.js:113:14) at where_ (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/ops/logical_ops.js:88:37) at Object.where (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/ops/operation.js:23:29) at Tensor.where (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/tensor.js:554:26) at Object.$x (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/ops/unary_ops.js:113:41) at Object.backpropagateGradients (/usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/tape.js:81:47) at /usr/local/google/home/cais/tfjs/tfjs-examples/mnist-node/node_modules/@tensorflow/tfjs-core/dist/engine.js:288:20

[nsthorat]

Just to diagnose this a little more, this is because of the loose versioning here: https://github.com/tensorflow/tfjs-node/blob/master/package.json#L42

Every time we add a kernel backend and update, you’ll break. I wonder if this should be an exact version. cc @dsmilkov

[kangyizhang]

This should because of some ops updates in tfjs-core KernelBackend. I’m updating NodeJSKernelBakcend to fix it.