CRAN - nurmi-labs/blogger GitHub Wiki
If you want a global directory for downloaded CRAN packages.
bash-4.3# usermod -a -G wheel eric
bash-4.3# mkdir -p /var/cache/cran
bash-4.3# chown -R root:wheel /var/cache/cran
bash-4.3# chmod -R 660 /var/cache/cran
bash-4.3#
Then in R, run for example install.packages("Rcpp", destdir = "/var/cache/cran")
.
cf: race conditions and synchronization
This approach is neither worth the effort to setup nor maintain on multi-user systems.