Django on Apache2 WSGI using wrong python

Question

I'm trying to run my Django website on Apache 2 using WSGI running Ubuntu 22 server, however I found that it is using the incorrect Python. When I try to connect to the website, it fails, and the error log reveals the following information:

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

Importing the numpy C-extensions failed. This error can happen for
many reasons, often due to issues with your setup or how NumPy was
installed.

We have compiled some common reasons and troubleshooting tips at:
  https://numpy.org/devdocs/user/troubleshooting-importerror.html

Please note and check the following:

* The Python version is: Python3.10 from "/var/www/djangoenv/bin/python"
 * The NumPy version is: "1.22.0"

and make sure that they are the versions you expect.
Please carefully study the documentation linked above for further help.
Original error was: No module named 'numpy.core._multiarray_umath'

The python and numpy are located in a virtual environment, and numpy has been indeed installed into this virtual environment. The numpy version is 1.22.0.

(djangoenv) ubuntu@server~$ python -V
Python 3.9.16

And we can see it is indeed located at the correct location (numpy):

(djangoenv) ubuntu@server:~$ ls /var/www/djangoenv/lib/python3.9/site-packages/ | grep numpy
numpy
numpy-1.22.0.dist-info

And the Virtual Host file in Apache2 is set accordingly:

website.conf Note: ServerName, Alias and domains replaced with xxxx for anonymization purposes

<VirtualHost *:80>

    ServerName xxxx
    ServerAlias xxxx

    Alias /static /var/www/djangoproject/static
    <Directory /var/www/djangoproject/static>
        Require all granted
    </Directory>

    <Directory /var/www/djangoproject/djangoproject>
        <Files wsgi.py>
            Require all granted
        </Files>
    </Directory>

    <Directory "/var/lib/letsencrypt/http_challenges">
        AllowOverride None
        Options -Indexes -FollowSymLinks
        # Allow open access:
        Require all granted
    </Directory>

    WSGIDaemonProcess djangoproject python-path=/var/www/djangoproject/var/www/djangoenv/lib/python3.9/site-packages python-home=/var/www/djangoenv
    WSGIProcessGroup djangoproject
    WSGIApplicationGroup %{GLOBAL}
    WSGIScriptAlias / /var/www/djangoproject/djangoproject/wsgi.py

    RewriteEngine on
    RewriteCond %{SERVER_NAME} =xxxx
    RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]

</VirtualHost>

And SSL version website-le-ssl.conf

<IfModule mod_ssl.c>
<VirtualHost *:443>

    ServerName xxxx
    ServerAlias xxxx

    Alias /static /var/www/djangoproject/static
    <Directory /var/www/djangoproject/static>
        Require all granted
    </Directory>

    <Directory /var/www/djangoproject/djangoproject>
        <Files wsgi.py>
            Require all granted
        </Files>
    </Directory>

#    WSGIDaemonProcess djangoproject python-path=/var/www/djangoproject:/var/www/djangoenv/lib/python3.9/site-packages
    WSGIProcessGroup djangoproject
    WSGIApplicationGroup %{GLOBAL}
    WSGIScriptAlias / /var/www/djangoproject/djangoproject/wsgi.py


    Include /etc/letsencrypt/options-ssl-apache.conf

    SSLCertificateFile /etc/letsencrypt/live/xxxx/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/xxxx/privkey.pem
</VirtualHost>
</IfModule>

This problem has been described and addressed in several SO threads and GitHub Issues but none of them seem to solve the issue.

Here is a list of things thus attempted:

• Upgrade NumPy using pip install --upgrade numpy
• Downgrade NumPy to 1.21.0
• Reinstall NumPy completely
• Install NumPy using pip install numpy==1.22.0 --no-binary=:all:
• Update WSGI by installing the Ubuntu 22 appropriate apt package
• Install mod-wsgi in the virtual environment itself

I can confirm that the django app works by itself by running

python manage.py runserver with no errors or issues.

Answer 1

Regarding this error:

No module named 'numpy.core._multiarray_umath'

I looked at your Apache configs and noticed this line in your HTTP (port 80) config:

    WSGIDaemonProcess djangoproject python-path=/var/www/djangoproject/var/www/djangoenv/lib/python3.9/site-packages python-home=/var/www/djangoenv

The value being passed to the python-path option looks incorrect:

/var/www/djangoproject/var/www/djangoenv/lib/python3.9/site-packages

It looks like it should be this instead:

/var/www/djangoenv/lib/python3.9/site-packages