In Roundup 0.7.1, the options list provided by
roundup-server includes:

 -g: sets the gid to this group after listening on the port

However, when attempting to use the option I get:

 option -g not recognized
Usage:
roundup-server [options] [name=tracker home]*
 
options:
 -v: print version and exit
 -n: sets the host name
 -p: sets the port to listen on (default: 8080)
 -u: sets the uid to this user after listening on the port
 -g: sets the gid to this group after listening on the port
 <SNIP> etc. etc.

Logged In: YES 
user_id=6405

Fixed in CVS. roundup/scripts/roundup_server.py has an options list that 
just doesn't list g: as an option.