Documentation for installing on Ubuntu outdated
Users searching for how to install R on Ubuntu probably end up on either of these pages: - https://cran.r-project.org/bin/linux/ubuntu/ - https://cran.r-project.org/bin/linux/ubuntu/fullREADME.html Which talk about the "current" R 4.2 release, and the latter document also goes on talking about 4.1 packages, and even an example of setting R_LIBS_USER for R-3.5.