IUnaryLayer cannot be used to compute a shape tensor


I want to convert my pytorch model to TensorRT format, first I convert to ONNX model, and the ONNX model works with ORT, then I tried to use trtexec to convert onnx model to TensorRT format, but failed with :

[12/22/2021-17:44:03] [E] Error[9]: [graph.cpp::computeInputExecutionUses::549] Error Code 9: Internal Error (Exp_641: IUnaryLayer cannot be used to compute a shape tensor)
[12/22/2021-17:44:03] [E] [TRT] ModelImporter.cpp:773: While parsing node number 664 [ConstantOfShape → “1127”]:
[12/22/2021-17:44:03] [E] [TRT] ModelImporter.cpp:774: — Begin node —
[12/22/2021-17:44:03] [E] [TRT] ModelImporter.cpp:775: input: “1126”
output: “1127”
name: “ConstantOfShape_664”
op_type: “ConstantOfShape”
attribute {
name: “value”
t {
dims: 1
data_type: 1
raw_data: “\000\000\000\000”
type: TENSOR

[12/22/2021-17:44:03] [E] [TRT] ModelImporter.cpp:776: — End node —
[12/22/2021-17:44:03] [E] [TRT] ModelImporter.cpp:779: ERROR: ModelImporter.cpp:179 In function parseGraph:
[6] Invalid Node - ConstantOfShape_664
[graph.cpp::computeInputExecutionUses::549] Error Code 9: Internal Error (Exp_641: IUnaryLayer cannot be used to compute a shape tensor)

The corresponding pytorch code is:
duration = (torch.exp(log_duration_prediction) - 1) * d_control

I see the TensorRT documents the exp op is supported, so I don’t know how to solve this issue.


TensorRT Version:
GPU Type: P40
Nvidia Driver Version: 470.82.01
CUDA Version: 11.4
CUDNN Version: 8.2.4
Operating System + Version: CentOS 7 3.10.0-1160.45.1.el7.x86_64
Python Version (if applicable): 3.7
TensorFlow Version (if applicable): NA
PyTorch Version (if applicable): 1.9
Baremetal or Container (if container which image + tag):

Request you to share the ONNX model and the script if not shared already so that we can assist you better.
Alongside you can try few things:

  1. validating your model with the below snippet


import sys
import onnx
filename = yourONNXmodel
model = onnx.load(filename)
2) Try running your model with trtexec command.
In case you are still facing issue, request you to share the trtexec “”–verbose"" log for further debugging

check_model does not report any error.

–verbose is already used in my log posted above.


Could you please share us issue repro onnx model for better debugging and provide fix.

Thank you.

I am also getting the same error, but likely due to a different model.

Here is a link to the onnx model and output from running trtexec --onnx=modified.onnx --verbose

check_model.py returns no errors.

I met the same problem like "IUnaryLayer cannot be used to compute a shape tensor " when I tried to get the shape value of ceil operation. I have tried may ways to change the realizations , but problem still alive . I wonder when this issue will be solved , next tensorrt release version or not sure ?

Many thanks

hi I am blocked by the same problem.
Has anyone figured out a solution, or workaround?