Import to gluon not working for ONNX model

[ankkhedia]

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Description

I tried to import the below model to gluon from ONNX. However, the import failed.
https://s3.amazonaws.com/onnx-model-zoo/arcface/resnet100/resnet100.onnx
This is a public S3 bucket.

Package used (Python/R/Scala/Julia):
I'm using python

Error Message:

[07/03/18 11:56 AM] Acharya, Anirudh: ---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
in ()
1 ctx = mx.cpu()
2 from mxnet.gluon import SymbolBlock
----> 3 net = SymbolBlock(outputs=sym, inputs=data_inputs)
4 net

/Users/aanirud/anaconda2/envs/mxnet2.7/lib/python2.7/site-packages/mxnet-1.3.0-py2.7.egg/mxnet/gluon/block.pyc in init(self, outputs, inputs, params)
1031 row_sparse_storage = ndarray.ndarray._STORAGE_TYPE_STR_TO_ID['row_sparse']
1032 for i in out:
-> 1033 for j in i.get_internals():
1034 assert(j.attr("storage_type") != str(row_sparse_storage)),
1035 "SymbolBlock doesn't support Parameter '%s' because its storage " \

/Users/aanirud/anaconda2/envs/mxnet2.7/lib/python2.7/site-packages/mxnet-1.3.0-py2.7.egg/mxnet/symbol/symbol.pyc in ((i,))
91
92 """
---> 93 return (self[i] for i in self.list_outputs())
94
95 def add(self, other):

/Users/aanirud/anaconda2/envs/mxnet2.7/lib/python2.7/site-packages/mxnet-1.3.0-py2.7.egg/mxnet/symbol/symbol.pyc in getitem(self, index)
515 if name == index:
516 if idx is not None:
--> 517 raise ValueError('There are multiple outputs with name "%s"' % index)
518 idx = i
519 if idx is None:

ValueError: There are multiple outputs with name "_mulscalar0_output"

Minimum reproducible example

Make a call to import_to_gluon API

[ankkhedia]

@sandeep-krishnamurthy Could you please tag this as ONNX?

[anirudhacharya]

I was able to import the above model into the symbolic interface

sym, arg_params, aux_params = onnx_mxnet.import_model("resnet100.onnx")

The error occurs when trying to create a SymbolBlock object from the symbol graph and the error is specific to this ONNX model only, it works fine with other models -

from mxnet.gluon import SymbolBlock
net = SymbolBlock(outputs=sym, inputs=data_inputs)

will debug it deeper.

[vandanavk]

Similar issue: https://discuss.mxnet.io/t/symbolblock-imports-valueerror-there-are-multiple-outputs-with-name/1599/3

[vandanavk]

@sandeep-krishnamurthy Please change the label to [Bug, Gluon]. The issue occurs on Gluon import of certain models (not ONNX format alone).

[sandeep-krishnamurthy]

@vandanavk - Can you please provide a minimum reproducible code in Gluon?

[vandanavk]

Sure. Here's the code snippet with ONNX model, https://s3.amazonaws.com/onnx-model-zoo/arcface/resnet100/resnet100.onnx

import mxnet as mx
from mxnet.gluon import SymbolBlock
from mxnet.contrib import onnx as onnx_mxnet

input_shape = (1, 3, 112, 112)
sym, arg_params, aux_params = onnx_mxnet.import_model("resnet100.onnx")
params = {}
params.update(arg_params)
params.update(aux_params)

net = SymbolBlock(outputs=sym, inputs=mx.sym.var('data'))

[piyushghai]

Similar issues perhaps : #12795 , #12794

[Roshrini]

@sandeep-krishnamurthy Can you please change the label to [Bug, Gluon]

[kalyc]

@ankkhedia can you re-try importing the models? The issue appears to have been fixed in the PR above

[ankkhedia]

@kalyc I tried running above code snippet with latest mxnet but it failed.
It seems the PR fixing the same issue has been closed and will be re-worked. #12805