cupsys package for sid

[Michal Hajek <hajek1@karlov.mff.cuni.cz>]

Hello everyone :)

I have following sources.list file 

deb http://debian-amd64.alioth.debian.org/debian-pure64 sid main contrib non-free
deb-src http://debian-amd64.alioth.debian.org/debian-pure64 sid main contrib non-free
############ mplayer
deb http://cyberspace.ucla.edu/marillat/ unstable main
deb ftp://ftp.nerim.net/debian-marillat/ unstable main


and I do not see any cupsys package among those listed in eg. aptitude. 
Perhaps I am doing something wrong, could someone please give me a hint? 

Thank you in advance. 

Best regards
Michal