How to sync cydia repository by ubuntu

1. apt-get install apt-mirror
2. Add cydia repository into /etc/apt/mirror.list
3. Change deb to deb-iphoneos-arm so that different arch could be loaded
ex.
original :
deb http://example.com/debian stable main contrib non-free
modified :
deb-iphoneos-arm http://example.com/debian stable main contrib non-free

4. Modify /usr/bin/apt-mirror to accept .bz2 only ( it seems that lots cydia repo did not provide .gz version of packages file )

5. run apt-mirror

After all done, mirrored repo could be found at /var/spool/apt-mirror/mirror
If anything failed during apt-mirror running, be sure to rm /var/spool/apt-mirror/var/apt-mirror.lock before re-run