Numpy: libf77blas.so.3: não é possível abrir o arquivo compartilhado: não existe esse arquivo ou diretório

-Sistema operacional: Raspbian Stretch (9)
-Como o Python foi instalado: Python 3.5.3 é o padrão Python3 no Stretch
-Como o numpy foi instalado: pip instalado no ambiente virtual (versão 1.17.3)
-Python2.7 também é instalado por padrão

Quero usar a biblioteca dldt do OpenVINO para inferência sobre o raspberry pi 3. Já tive problemas antes, mas seguindo algumas instruções aqui , construí a versão mais recente da biblioteca usando o cmake para compilação nativa sob o raspbian stretch (levou horas).

Notei pela primeira vez o erro ao executar o código python do otimizador de modelo:

$ python3 <dldt_dir>/model-optimizer/mo.py --input_model [input model] --data_type [data type] --output_dir [output_dir]
Traceback (most recent call last):
  File "/home/pi/.virtualenvs/openvino/lib/python3.5/site-packages/numpy/core/__init__.py", line 17, in <module>
    from . import multiarray
  File "/home/pi/.virtualenvs/openvino/lib/python3.5/site-packages/numpy/core/multiarray.py", line 14, in <module>
    from . import overrides
  File "/home/pi/.virtualenvs/openvino/lib/python3.5/site-packages/numpy/core/overrides.py", line 7, in <module>
    from numpy.core._multiarray_umath import (
ImportError: libf77blas.so.3: cannot open shared object file: No such file or directory

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/pi/.virtualenvs/openvino/lib/python3.5/site-packages/numpy/__init__.py", line 142, in <module>
    from . import core
  File "/home/pi/.virtualenvs/openvino/lib/python3.5/site-packages/numpy/core/__init__.py", line 47, in <module>
    raise ImportError(msg)
ImportError: 

IMPORTANT: PLEASE READ THIS FOR ADVICE ON HOW TO SOLVE THIS ISSUE!

Importing the numpy c-extensions failed.
- Try uninstalling and reinstalling numpy.
- If you have already done that, then:
  1. Check that you expected to use Python3.5 from "/home/pi/.virtualenvs/openvino/bin/python",
     and that you have no directories in your PATH or PYTHONPATH that can
     interfere with the Python and numpy version "1.17.3" you're trying to use.
  2. If (1) looks fine, you can open a new issue at
     https://github.com/numpy/numpy/issues.  Please include details on:
     - how you installed Python
     - how you installed numpy
     - your operating system
     - whether or not you have multiple versions of Python installed
     - if you built from source, your compiler versions and ideally a build log

- If you're working with a numpy git repository, try `git clean -xdf`
  (removes all files not under version control) and rebuild numpy.

Note: this error has many possible causes, so please don't comment on
an existing issue about this - open a new one instead.

Original error was: libf77blas.so.3: cannot open shared object file: No such file or directory

No entanto, descobri rapidamente que esse problema persiste ao importar numpy do Python3

>>> import numpy as np
[...]
Importing the numpy c-extensions failed.
[...]
Original error was: libf77blas.so.3: cannot open shared object file: No such file or directory

Eu tentei desinstalar e reinstalar o numpy. Verifiquei se o numpy funcionou no Python3 antes de instalar a biblioteca dldt.
Por favor ajude. Você é minha única esperança.