This is truly odd...

This works fine for me:

$ sudo ./althttpd -port 80 -root $PWD -logfile /dev/stderr -user stephan
^C

But this ostensible equivalent fails (the only difference is the lack of -port 80):

$ sudo ./althttpd -root $PWD -logfile /dev/stderr -user stephan

 400 Bad Request
Connection: close
Date: Tue, 01 Feb 2022 04:50:43 GMT
Content-type: text/plain; charset=utf-8

This server does not understand the requested protocol

That message shows up as soon as i tap ENTER in the console (after the ENTER to run the command). Before that point, the browser cannot connect, as if port 80 is simply not in use.

Interesting...

$ ~/bin/althttpd -port 8080 -root ~/www `

The shell (bash) looks like it kills althttpd, but the process is still running. I don't know what would make it look like the process isn't running anymore.