Uninstalling the R development toolchain on macOS

If you previously used either the clang4, clang6, clang7, gfortran 6.1, or the macos-rtools installer, please consider deleting the old components that were installed.

Note: Special care should be taken when removing files with the rm command. Make sure the commands and file paths are copied in verbatim to a text editor and, then, run in Terminal.

To do so, open the Terminal from /Applications/Utilities/ and type:

# Delete the clang4,6,7 binary
sudo rm -rf /usr/local/clang{4,6,7}

# Delete the prior version of gfortran installed
sudo rm -rf /usr/local/gfortran
sudo rm -rf /usr/local/bin/gfortran

# Remove the install receipts that indicate a package is present

# Remove the gfortran install receipts (run after the above commands)
sudo rm /private/var/db/receipts/com.gnu.gfortran.bom
sudo rm /private/var/db/receipts/com.gnu.gfortran.plist

# Remove the clang4 installer receipt
sudo rm /private/var/db/receipts/com.rbinaries.clang4.bom
sudo rm /private/var/db/receipts/com.rbinaries.clang4.plist

In the prior configuration for R 3.4.x, we did a lot of configuration in ~/.R/Makevars. From R 3.5.z to R 3.6.z, the configuration method changes to modify the PATH variable using ~/.Renviron file and adding compilation flags to ~/.R/Makevars. Therefore, removing the old files installed to obtain a “fresh” slate is useful to ensure everything was configured correctly.

# Remove the Makevars file
rm ~/.R/Makevars

# Remove the Renviron file
rm ~/.Renviron

Note: If you are upgrading from R 3.0.0 - R 3.3.3 to any later R version, you may have the old CRAN compiled gfortran4.8.2 binary. Please see the instructions at Removing the old R gfortran binary for assistance in removing the binary.