The packages in Yun Rev 2 only have version 1.0.x versus what use to be their in other Yun's I've had in the past.
I found the following by "googling" around;
I found a copy of rrdtool_1.2.30-3_ar71xx.ipk at the following location;
I also found for the Artheros version (which is what the Yun is AR9331);
Both repositories are missing the Packages.sig file and probably other files that are in the newer repositories that I see. Anyway to install the ipk file directly or was it complied under an older release and isn't going to work?