I have tried every install method I can think of to install RPy2 on our debian server and I get the same message regardless. I have installed and used it successfully on my mac.
If you compile R with
./configure --enable-R-shlib, then R is installed in /usr/local/lib/R
./configure --enable-R-shlib
/usr/local/lib/R
So you can add this lines to .bashrc, for you and root user
export R_HOME=/usr/local/lib/R export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$R_HOME/lib
Then you can install from pip or build from tarball