How can I set an environment variable (not an "Apache environment variable", as described in the Apache HTTP server documentation here, but a plain old operating system environment variable) for processes spawned by Apache HTTP server?
I have a Flask WSGI application for which I would like to have an environment variable set for the user www-data
under which the HTTP server runs.
This is basically the same as the question How to set an environment variable for a process spawned by the webserver?, except for Apache HTTP server.