How to set a user package library in R

R searches an ordered set of library directories whenever it installs or loads an add-on package. A personal library puts one account's packages first without granting write access to system-wide R directories.

The R_LIBS_USER environment variable supplies that directory during startup, and ~/.Renviron stores environment variables for one user. R retains only library directories that exist when the session starts, so create the directory before starting the session that checks the change.

A fixed ~/R/library path keeps the same location across R minor releases. Packages containing compiled code may still require reinstallation after an R upgrade, while site and system libraries remain later in .libPaths() for administrator-managed packages.

1. Create the personal R package directory.

   $ mkdir -p ~/R/library

2. Open the per-user environment file in nano.

   $ nano ~/.Renviron

3. Add the R_LIBS_USER setting on a new line.

   R_LIBS_USER="${HOME}/R/library"

   The ${HOME} expansion avoids embedding an account name in the configuration.

4. Save ~/.Renviron in nano.
5. Exit nano to return to the shell.
6. Start a fresh R session without restoring a saved workspace.

   $ R --quiet --no-save
   >

   R reads ~/.Renviron during startup. An existing session does not rebuild its library path after the file changes.

7. Confirm the personal directory appears first in the active library search path.

   > .libPaths()
   [1] "/home/analyst/R/library"       "/usr/local/lib/R/site-library"
   [3] "/usr/lib/R/site-library"       "/usr/lib/R/library"

   The home directory differs by account and operating system. The important state is that the writable personal directory appears before the site and system libraries.

8. Install the crayon test package into the active personal library.

   > install.packages("crayon", repos = "https://cloud.r-project.org")
   Installing package into '/home/analyst/R/library'
   (as 'lib' is unspecified)
   trying URL 'https://cloud.r-project.org/src/contrib/crayon_1.5.3.tar.gz'
   ##### snipped #####
   * DONE (crayon)

   Related: How to install an R package from CRAN

9. Resolve the installed crayon namespace path from the active library search path.

   > getNamespaceInfo(loadNamespace("crayon"), "path")
   [1] "/home/analyst/R/library/crayon"