Comment 40 for bug 1417608

Kalpana, Pavithra, "unstable" is from Debian. Launchpad mirrors Debian's packages, which can be retrieved by hand if that's easier.

For e.g. the iprutils source package in Ubuntu:
https://launchpad.net/ubuntu/+source/iprutils
The corresponding source packages in Debian are mirrored to:
https://launchpad.net/debian/+source/iprutils

The corresponding apt sources should be something like:
deb http://ftp.us.debian.org/debian/ sid main
deb-src http://ftp.us.debian.org/debian/ sid main

Be careful mixing Debian and Ubuntu sources if you test this on an Ubuntu system.

Thanks