Overview

Dealing with R Packages can be a pain sometimes, especially when dealing with development versions of evolving packages over time. Additionally, sometimes it is necessary to revert back to an old version of a package in order to reproduce an old project or replicate a test environment for a deployment.

To resolve some of the pains associated with this process, I came up with a nice little solution, which I will explain in this post.

Setup Personal Libraries

The goal is to have additional system wide libraries for Dev packages as well as Old versions of packages, in addition to your default .libPaths() user library.

For me this is how I set up the folders:

To do this I ran the following code:

dev_path <- gsub("4.0", "Dev", .libPaths()[1])
dir.create(dev_path)

old_path <- gsub("4.0", "Old", .libPaths()[1])
dir.create(old_path)

However, we need a way for these libPaths to be accessible from R.

Setting up RProfile

To do this you could utilize the Windows Environment Variable Paths (like the default library path does), but instead I decided on a simpler method via the .Rprofile startup dotfile.

To access your .Rprofile you can run usethis::edit_r_profile().

Here are the lines of code I added to my .Rprofile which add these new paths as internal R Options (so as to keep them hidden from the environment variables):

options(
    "dev_lib" = gsub("4.0", "Dev", .libPaths()[1]),
    "old_lib" = gsub("4.0", "Old", .libPaths()[1])
)

Now every time R is loaded I can access these library paths via getOption("dev_lib") or getOption("old_lib").

Adding Packages

Now, we want to add some packages to the newly created Dev and old package libraries.

For example, let’s say I need the old version of dplyr (v0.8.5) instead of the current v1.0.0. I can install it into the old_lib via:

remotes::install_version("dplyr", 
                         version = "0.8.5",
                         lib = getOption("old_lib"),
                         upgrade = "never")

and library it using:

library("dplyr", lib.loc = getOption("old_lib"))

Notice my use of the argument upgrade = "never" in my call to remotes::install_version.

Alternatively, let’s say I want the development version of the shiny package in my dev_lib to try out new features not yet on CRAN:

remotes::install_github("shiny", 
                        lib = getOption("dev_lib"), 
                        upgrade = "always")

and to library…

library("shiny", lib.loc = getOption("dev_lib"))

Additional Resources

If you would like to take this idea a little further, you should look into creating project specific libraries using the renv package.