Bug: TypeError: Builder.EndVector() missing 1 required positional argument: 'vectorNumElems' #937
Description
What happened?
I'm trying to export tflite model by using ultralytics YOLO, but it will be requested install tensorflow. When has been done , onnx model and Tensorflow SaveModel can be converted. Then starting TFLite export with onnx2tf showed a bug, TypeError: Builder.EndVector() missing 1 required positional argument: 'vectorNumElems'
Relevant code
export_model.py file:
from ultralytics import YOLO
glass_model = "./model/glass_detect.pt"
model = YOLO(glass_model)
model.export(format="tflite")Relevant log output
TensorFlow SavedModel: starting export with tensorflow 2.19.1...
ONNX: starting export with onnx 1.20.1 opset 22...
python3.10/site-packages/torch/onnx/_internal/torchscript_exporter/utils.py:1447: OnnxExporterWarning: Exporting to ONNX opset version 22 is not supported. by 'torch.onnx.export()'. The highest opset version supported is 20. To use a newer opset version, consider 'torch.onnx.export(..., dynamo=True)'
warnings.warn(python3.10/site-packages/torch/onnx/_internal/torchscript_exporter/symbolic_opset9.py:5353: UserWarning: Exporting aten::index operator of advanced indexing in opset 22 is achieved by combination of multiple ONNX operators, including Reshape, Transpose, Concat, and Gather. If indices include negative values, the exported graph will produce incorrect results.
warnings.warn(ONNX: slimming with onnxslim 0.1.82...2026-01-22 10:34:58.241526636 [W:onnxruntime:Default, device_discovery.cc:164 DiscoverDevicesForPlatform] GPU device discovery failed: device_discovery.cc:89 ReadFileContents Failed to open file: "/sys/class/drm/card1/device/vendor"
ONNX: export success 1.9s, saved as 'model/glass_detect.onnx' (9.0 MB)
TensorFlow SavedModel: starting TFLite export with onnx2tf 1.28.8...
Saved artifact at 'model/glass_detect_saved_model'. The following endpoints are available:
...
...
...
WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
I0000 00:00:1769049317.419732 6726 devices.cc:76] Number of eligible GPUs (core count >= 8, compute capability >= 0.0): 0 (Note: TensorFlow was not compiled with CUDA or ROCm support)
WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
I0000 00:00:1769049317.420113 6726 single_machine.cc:374] Starting new session
W0000 00:00:1769049318.338438 6726 tf_tfl_flatbuffer_helpers.cc:365] Ignored output_format.
W0000 00:00:1769049318.338498 6726 tf_tfl_flatbuffer_helpers.cc:368] Ignored drop_control_dependency.
ERROR TensorFlow SavedModel: export failure 35.2s: Builder.EndVector() missing 1 required positional argument: 'vectorNumElems'
Traceback (most recent call last):
File "export_model.py", line 12, in <module>
model.export(format="tflite")
File "python3.10/site-packages/ultralytics/engine/model.py", line 710, in export
return Exporter(overrides=args, _callbacks=self.callbacks)(model=self.model)
File "python3.10/site-packages/ultralytics/engine/exporter.py", line 581, in __call__
f[5], keras_model = self.export_saved_model()
File "python3.10/site-packages/ultralytics/engine/exporter.py", line 249, in outer_func
raise e
File "python3.10/site-packages/ultralytics/engine/exporter.py", line 241, in outer_func
f = inner_func(*args, **kwargs) # exported file/dir or tuple of (file/dir, *)
File "python3.10/site-packages/ultralytics/engine/exporter.py", line 1085, in export_saved_model
keras_model = onnx2saved_model(
File "python3.10/site-packages/ultralytics/utils/export/tensorflow.py", line 114, in onnx2saved_model
keras_model = onnx2tf.convert(
File "python3.10/site-packages/onnx2tf/onnx2tf.py", line 1574, in convert
tflite_model = converter.convert()
File "python3.10/site-packages/tensorflow/lite/python/lite.py", line 2360, in convert
return super(TFLiteConverterV2, self).convert()
File "python3.10/site-packages/tensorflow/lite/python/lite.py", line 1250, in wrapper
return self._convert_and_export_metrics(convert_func, *args, **kwargs)
File "python3.10/site-packages/tensorflow/lite/python/lite.py", line 1222, in _convert_and_export_metrics
return flatbuffer_utils.convert_object_to_bytearray(model_object)
File "python3.10/site-packages/tensorflow/lite/tools/flatbuffer_utils.py", line 122, in convert_object_to_bytearray
model_offset = model_object.Pack(builder)
File "python3.10/site-packages/tensorflow/lite/python/schema_py_generated.py", line 18605, in Pack
operatorCodes = builder.EndVector()
TypeError: Builder.EndVector() missing 1 required positional argument: 'vectorNumElems'tensorflow_hub Version
other (please specify)
TensorFlow Version
other (please specify)
Other libraries
Package Version
absl-py 2.3.1
ai-edge-litert 2.1.0
astunparse 1.6.3
backports.strenum 1.3.1
certifi 2026.1.4
charset-normalizer 3.4.4
colorama 0.4.6
coloredlogs 15.0.1
contourpy 1.3.2
cycler 0.12.1
filelock 3.20.3
flatbuffers 20181003210633
fonttools 4.61.1
fsspec 2026.1.0
gast 0.7.0
google-auth 2.47.0
google-auth-oauthlib 1.2.4
google-pasta 0.2.0
grpcio 1.76.0
h5py 3.15.1
humanfriendly 10.0
idna 3.11
Jinja2 3.1.6
keras 3.12.0
kiwisolver 1.4.9
libclang 18.1.1
Markdown 3.10
markdown-it-py 4.0.0
MarkupSafe 3.0.3
matplotlib 3.10.8
mdurl 0.1.2
ml_dtypes 0.5.4
mpmath 1.3.0
namex 0.1.0
networkx 3.4.2
numpy 1.26.4
oauthlib 3.3.1
onnx 1.20.1
onnx_graphsurgeon 0.5.8
onnx2tf 1.28.8
onnxruntime 1.23.2
onnxslim 0.1.82
opencv-python 4.13.0.90
opt_einsum 3.4.0
optree 0.18.0
packaging 25.0
pillow 12.1.0
pip 25.3
polars 1.37.1
polars-runtime-32 1.37.1
protobuf 6.33.4
psutil 7.2.1
pyasn1 0.6.2
pyasn1_modules 0.4.2
Pygments 2.19.2
pyparsing 3.3.2
python-dateutil 2.9.0.post0
PyYAML 6.0.3
requests 2.32.5
requests-oauthlib 2.0.0
rich 14.2.0
rsa 4.9.1
scipy 1.15.3
setuptools 80.9.0
six 1.17.0
sng4onnx 1.0.4
sympy 1.14.0
tensorboard 2.19.0
tensorboard-data-server 0.7.2
tensorflow 2.19.1
tensorflow-cpu-aws 2.15.0
tensorflow-estimator 2.15.0
tensorflow-io-gcs-filesystem 0.37.1
termcolor 3.3.0
tf_keras 2.19.0
torch 2.9.1
torchvision 0.24.1
tqdm 4.67.1
typing_extensions 4.15.0
ultralytics 8.4.6
ultralytics-thop 2.0.18
urllib3 2.6.3
Werkzeug 3.1.5
wheel 0.45.1
wrapt 1.14.2
Python Version
3.x
OS
Linux