apt install mercurial uwsgi-core uwsgi-plugins-all

Application

foobar.py

def application(env, start_response):
    start_response('200 OK', [('Content-Type','text/html')])
    return [b"Hello World"]

Server

uwsgi --plugins http,python3 --http :9090 --wsgi-file foobar.py

Client

$ telnet 127.0.0.1 9090
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
HEAD / HTTP/1.0

HTTP/1.0 200 OK
Content-Type: text/html

Hello World

bill$ cat /var/www/cgi-bin/hgweb.wsgi
config = b"/var/www/repos/WWW.EXAMPLE.COM/hgweb.config"
import os
os.environ["HGENCODING"] = "UTF-8"
import cgitb; cgitb.enable()
from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb
application = hgweb(config)

#! /bin/bash

#LOG
exec 2>&1
ulimit -l unlimited
ulimit -i unlimited
ulimit -q unlimited
ulimit -n 8192
ulimit -aH

#RUN
export TZ="UTC"
exec /bin/uwsgi --plugins http,python3 --http :9090 --master --processes 4 --threads 2 --uid=www-data --gid=www-data --wsgi-file /var/www/cgi-bin/hgweb.wsgi

NGINX setup

UWSGI