pgAdmin4 install - Target WSGI script cannot be loaded as Python module

This question has been asked before here but the solution does not work for me. My python venv configuration is not playing well with the apache2 mod_wsgi and I cannot root-cause the issue. At present, I cannot comment on this question so I'm posting another one

Here are the apache2 error logs when trying to log into the site.

[Fri Dec 07 20:32:25.476491 2018] [wsgi:warn] [pid 25982:tid 140573456193408] mod_wsgi: Compiled for Python/3.5.1+.
[Fri Dec 07 20:32:25.476529 2018] [wsgi:warn] [pid 25982:tid 140573456193408] mod_wsgi: Runtime using Python/3.5.2.
[Fri Dec 07 20:32:25.477326 2018] [mpm_event:notice] [pid 25982:tid 140573456193408] AH00489: Apache/2.4.18 (Ubuntu) mod_wsgi/4.3.0 Python/3.5.2 configured -- resuming normal operations
[Fri Dec 07 20:32:25.477362 2018] [core:notice] [pid 25982:tid 140573456193408] AH00094: Command line: '/usr/sbin/apache2'
[Fri Dec 07 20:34:24.401510 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047] mod_wsgi (pid=25983): Target WSGI script '/home/awashburn/anaconda3/envs/pgadmin4/lib/python3.7/site-packages/pgadmin4/pgAdmin4.wsgi' cannot be loaded as Python module.
[Fri Dec 07 20:34:24.401642 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047] mod_wsgi (pid=25983): Exception occurred processing WSGI script '/home/awashburn/anaconda3/envs/pgadmin4/lib/python3.7/site-packages/pgadmin4/pgAdmin4.wsgi'.
[Fri Dec 07 20:34:24.402195 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047] Traceback (most recent call last):
[Fri Dec 07 20:34:24.402229 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047]   File "/home/awashburn/anaconda3/envs/pgadmin4/lib/python3.7/site-packages/pgadmin4/pgAdmin4.wsgi", line 25, in <module>
[Fri Dec 07 20:34:24.402236 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047]     import config
[Fri Dec 07 20:34:24.402244 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047]   File "/home/awashburn/anaconda3/envs/pgadmin4/lib/python3.7/site-packages/pgadmin4/config.py", line 29, in <module>
[Fri Dec 07 20:34:24.402248 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047]     from pgadmin.utils import env, IS_PY2, IS_WIN, fs_short_path
[Fri Dec 07 20:34:24.402256 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047]   File "/home/awashburn/anaconda3/envs/pgadmin4/lib/python3.7/site-packages/pgadmin4/pgadmin/__init__.py", line 18, in <module>
[Fri Dec 07 20:34:24.402260 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047]     from flask import Flask, abort, request, current_app, session, url_for
[Fri Dec 07 20:34:24.402280 2018] [wsgi:error] [pid 25983:tid 140573343934208] [remote 10.2.5.243:15047] ImportError: No module named 'flask'

Here is the Vhost configuration:

<VirtualHost *>
    ServerName shinyapp01t

    WSGIDaemonProcess pgadmin processes=1 threads=25 python-home=/home/awashburn/anaconda3/envs/pgadmin4 display-name=pgadmin4
    WSGIScriptAlias /pgadmin /home/awashburn/anaconda3/envs/pgadmin4/lib/python3.7/site-packages/pgadmin4/pgAdmin4.wsgi

    <Directory "/home/awashburn/anaconda3/envs/pgadmin4/lib/python3.7/site-packages/pgadmin4/">
        WSGIProcessGroup pgadmin
        WSGIApplicationGroup %{GLOBAL}
        Require all granted
    </Directory>
</VirtualHost>

I referenced these instructions from DigitalOcean trying to install pgAdmin4 on Ubuntu 16.04.

Edit: I used a python3 venv instead of anaconda virtual env and everything worked fine. So the root cause is the anaconda system. There's a discussion on the mod_wsgi mailing list about this