Comment # 2 on bug 1215586 from Charles Arnold

(In reply to Olaf Hering from comment #1)
> I think this can be solved with 'sort -u appliance/packagelist >
> %buildroot%_libdir/guestfs/supermin.d/packages' somewhere in %install.

I'll look into doing this. In the meantime, I've added sysconfig-netconfig to
the BuildRequires for the quick fix.