Using TPU: AttributeError: 'Delegate' object has no attribute '_library'

[airqualityanthony]

Running the docker as per the file instructions - RPi 4 with a TPI.

Trying to run the command: umt -video highway_01.mp4 -tpu

I get the following:

> INITIALIZING UMT...
   > THRESHOLD: 0.5
   > CUSTOM LABEL MAP = FALSE
   > TPU = TRUE
   > CUSTOM DETECTOR = FALSE
Traceback (most recent call last):
  File "/usr/local/bin/umt", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.7/dist-packages/umt/umt_main.py", line 62, in main
    interpreter = initialize_detector(args)
  File "/usr/local/lib/python3.7/dist-packages/umt/umt_utils.py", line 110, in initialize_detector
    {'device': device[0]} if device else {})
  File "/usr/local/lib/python3.7/dist-packages/tflite_runtime/interpreter.py", line 152, in load_delegate
    delegate = Delegate(library, options)
  File "/usr/local/lib/python3.7/dist-packages/tflite_runtime/interpreter.py", line 81, in __init__
    self._library = ctypes.pydll.LoadLibrary(library)
  File "/usr/lib/python3.7/ctypes/__init__.py", line 434, in LoadLibrary
    return self._dlltype(name)
  File "/usr/lib/python3.7/ctypes/__init__.py", line 356, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: libedgetpu.so.1: cannot open shared object file: No such file or directory
Exception ignored in: <function Delegate.__del__ at 0xa819b198>
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/dist-packages/tflite_runtime/interpreter.py", line 116, in __del__
    if self._library is not None:
AttributeError: 'Delegate' object has no attribute '_library'

It works fine when I run without the tpu argument. I have the tpu installed correctly, and works for other code outside the docker.

Any help?

Thanks,

Anthony

[airqualityanthony]

I think the issue is the installation of the tflite runtime and edgetpu libraries have been updated. I had to edit the dockerfile to contain the following:

# install tflite runtime
RUN apt-get install -y apt-utils
RUN apt-get install -y curl
RUN echo "deb https://packages.cloud.google.com/apt coral-edgetpu-stable main" | tee /etc/apt/sources.list.d/coral-edgetpu.list
RUN curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
RUN apt-get update -y
RUN apt-get install -y libedgetpu1-std
RUN apt-get install -y python3-pycoral

Seems to work ok.

[airqualityanthony]

@nathanrooy I'll close out, suggest the above changes to be implemented for latest installation. Feel free to check and edit if necessary.