so I thought I should get it.
But for some reason the rocketfuel-setup couldn't download
the keys it wanted for the dependencies it needed to apt-get:
Retrieving key 0A5174AF.
gpg: requesting key 0A5174AF from hkp server keyserver.ubuntu.com
gpgkeys: key 0A5174AF not found on keyserver
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
Could not retrieve key 0A5174AF.
So after mucking around trying to tell it to use my proxy,
I just commented out the relevant exit 1 lines.
This worked great, I just got prompted to confirm I want to install these packages.
I suppose the better solution would have been to try harder to manually install
the keys, but I didn't want to think about it too much.