Developer install: failure to launch; multiarray numpy extension module failed

I suspect this has something to do with multiple python versions. I'm working with a fresh install of Raspbian on a RPi3, following Developer install steps using Poetry.

uname -a Linux raspberrypi 4.19.42-v7+ #1219 SMP Tue May 14 21:20:58 BST 2019 armv7l GNU/Linux

Install Steps followed: pi@raspberrypi:~ $ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 1

pi@raspberrypi:~ $ sudo update-alternatives --config python There is only one alternative in link group python (providing /usr/bin/python): /usr/bin/python3

pi@raspberrypi:~ $ sudo apt-get install libatlas-base-dev libjasper-dev libjpeg-dev

pi@raspberrypi:~ $ python -m virtualenv ~/.openflexure/envmicroscope

pi@raspberrypi:~ $ source ~/.openflexure/envmicroscope/bin/activate

(envmicroscope) pi@raspberrypi:~ $ curl -sSL https://raw.githubusercontent.com/sdispater/poetry/master/get-poetry.py | python (envmicroscope) pi@raspberrypi:~ $ source ~/.poetry/env

(envmicroscope) pi@raspberrypi:~ $ poetry --version Poetry 0.12.16

(envmicroscope) pi@raspberrypi:~ $ git clone https://gitlab.com/openflexure/openflexure-microscope-server.git (envmicroscope) pi@raspberrypi:/openflexure-microscope-server $ poetry install (envmicroscope) pi@raspberrypi:/openflexure-microscope-server $ pip install gunicorn

(envmicroscope) pi@raspberrypi:~/openflexure-microscope-server $ gunicorn --threads 5 --workers 1 --graceful-timeout 3 --bind 0.0.0.0:5000 openflexure_microscope.api.app:app ... Importing the multiarray numpy extension module failed. ... Original error was: libf77blas.so.3: cannot open shared object file: No such file or directory ...

(envmicroscope) pi@raspberrypi:~ $ pip install numpy

Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple Requirement already satisfied: numpy in ./.openflexure/envmicroscope/lib/python3.5/site-packages (1.16.1)