Install jigdo-file
To build snapshot of sid distribution:
$ jigdo-lite ftp://ftp.fsn.hu/pub/CDROM-Images/debian-unofficial/sid/jigdo/sid-i386-1.iso.jigdo <ENTER> ftp://mirror.aarnet.edu.au/pub/debian/ ftp://mirror.aarnet.edu.au/pub/linux/debian-non-US/