Hi Ross:

I'm sorry you are running into issues with Roundup.

I tried to duplicate your steps but I am using linux mint 22.3, python 3.12, and firefox 
146.0.1.

Note that 3.9 Python support maybe dropped in Roundup 2.6 due for release in July.
You are running 2.6 by using the repository version rather than a released pip
installed version of Roundup. However, what you are seeing is not expected.

> 127.0.0.1 - - [18/May/2026 06:15:49] "POST /demo/ HTTP/1.1" 302 -
> 127.0.0.1 - - [18/May/2026 06:15:49] "GET /demo/?%40ok_message=Welcome+demo%21 HTTP/1.1" 
200 -
> 127.0.0.1 - - [18/May/2026 06:15:49] "GET /demo/rest HTTP/1.1" 200 -
> 127.0.0.1 - - [18/May/2026 06:15:49] "GET /favicon.ico HTTP/1.1" 200 -
> 127.0.0.1 - - [18/May/2026 06:15:49] "GET /favicon.ico HTTP/1.1" 400 -
> EXCEPTION AT Mon May 18 06:15:49 2026

This is odd, you shouldn't have two favicon requests. Also they shouldn't have
two different statuses: 200 and 400.

When I duplicated your steps, the logging looked the same up to the GET /demo/rest.

After that I do not have the favicon.ico requests. (favicon.ico should have been cached
when the browser loaded the login screen.)

I have a GET for "/demo/?%40template=translation&properties ....." which is the 
classhelper.js module getting translated strings for its interface. Do you have
javascript enabled on your browser?

While I do not get an exception, I get three timeouts after a minute which is expected.

My claim is something is closing the browser/roundup connection.
I am not sure what. Are you experienced in using the firefox devtools, maybe
something on the network tab may shed some light on this.

On the bright side, I think you may have given me a solution to another issue.
It looks like the BrokenPipeError should be trapped and discarded like a 
ConnectionAbortedError.

Roundup runs in many different environments:

   stand alone server (which is used by demo.py)
   behind a proxy (e.g. pound, apache, nginx ... in reverse proxy mode)
   as a wsgi process using a wsgi server (gunicorn, Waitress)
   as a Zope framework module

and all of these handle and expose network and other errors a little differently.

Even though Roundup should not be seeing a BrokenPipeError, it should be handled better.
I'll see if I can make some changes to handle it better.

-- rouilj