Created by: chenwhql
Related issue: https://github.com/PaddlePaddle/Paddle/issues/11371#issuecomment-547769713
Add user-friendly error message hint for fc(mul) when users not invoke exe.run(startup_progrom).
The result is as follow:
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Error Message Summary:
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PaddleCheckError: Expected framework::product(y_dims) != 0, but received framework::product(y_dims):0 == 0:0.
Maybe the Input variable Y(fc_0.w_0) has not been initialized. You may need to confirm if you put exe.run(startup_program) after optimizer.minimize function. at [/work/paddle/paddle/fluid/operators/mul_op.cc:56]
[operator < mul > error]