Import frozen graph of a LSTM has an error

Using Tensorflow v1.11.0.

Please see here to reproduce the error: https://github.com/esdu/misc/blob/master/bug_report_lstm_freeze.ipynb

In the above notebook, I train a simple LSTM, try to freeze the graph, and load the frozen graph. Upon loading the frozen graph, I see an error:

InvalidArgumentError: Input 0 of node import/lstm/while/ReadVariableOp/Enter was passed float from import/lstm/kernel:0 incompatible with expected resource.

The lstm/kernel node was frozen into a Const, and lstm/while/ReadVariableOp/Enter cannot read it in. The same thing is observed for other variables related to the LSTM: lstm/bias and lstm/recurrent_kernel.

Any hints on how to freeze an LSTM trained in Keras?

[fafo]

Same behaviour here. convert_variables_to_constants changes ReadVariableOps to Identity nodes after transforming computed variables to constants. However some variables are attached to Enter nodes which are incompatible with the generated constants (eg. they expect a resource and they receive a flot). Any idea how can we fix Enter nodes?

[chris0914]

Same error occurs, when using Autograph with LSTM-layer. Running the current master branch on commit 7c5157667006181f16efa3b70468ec1bd62cb070. Any news on how to fix this?