[synfig@vps ~]$ mock init -r fedora-8-i386     
init
clean
prep
This may take a while
Error performing yum command: /usr/sbin/mock-helper yum --installroot /var/lib/mock/fedora-8-i386/root groupinstall buildsys-build
ending
done
[synfig@vps ~]$ /usr/sbin/mock-helper yum --installroot /var/lib/mock/fedora-8-i386/root groupinstall buildsys-build
Failed to add groups file for repository: fedora
Failed to add groups file for repository: updates-released
Error: No Groups on which to run command
[synfig@vps ~]$ id
uid=504(synfig) gid=504(synfig) groups=101(mock),504(synfig)