Jake Elmstedt
2021-May-24 23:35 UTC
[Rd] Locking of base environment in R 4.1.0 breaks simple assignment of .First() (etc) from Rprofile.site
Commits 80162 and 80163 lock the base environment and namespace during startup, leading to an error when attempting to directly assign anything from within Rprofile.site. While this is intentional and good, the help file has not been updated to reflect this change. Startup.Rd ( Description, paragraph 3) reads,> ...This code is sourced into the base package. Users need to be carefulnot to unintentionally overwrite objects in base, and it is normally advisable to use local if code needs to be executed: see the examples. Since the base environment and namespace are locked as of 4.1.0, I recommend this be edited to something to the effect of:> Prior to R 4.1.0, this code is sourced into the base package. Users needto be careful not to unintentionally overwrite objects in base, and it is normally advisable to use local if code needs to be executed: see the examples. As of R 4.1.0 the base environment and namespace are locked and any attempted direct assignment will fail with an error, and none of the subsequent commands will be invoked. Users migrating to R 4.1.0 and above can edit assignments made in Rprofile.site from the form `x <- value` to `assign("x", value, envir = globalenv())`. Common uses of this may include the binding of functions `.First` and `.Last`. Description paragraph 8,> "A function .First (and .Last) can be defined in appropriate ?.Rprofile?or ?Rprofile.site? files..." which might be misleading to users not well-versed in the intricacies of the R startup process. Should this be edited to indicate variable assignment from Rprofile.site must be done using assign() to bind them to globalenv()? Something to the effect of,> A function .First (and .Last) can be defined in appropriate ?.Rprofile?or ?Rprofile.site? files (note: as of R 4.1.0, assignments from Rprofile.site must target the global environment, e.g. use `assign(".First", function(){}, envir = globalenv())` rather than `.First <- function(){}`) or have been saved in ?.RData?. I also recommend adding to Examples, under the Example of Rprofile.site section, something to the effect of, # Setting .First and .Last from within Rprofile.site requires # assignment into the global environment for R versions # 4.1.0 and later and is a best practice for earlier versions. assign(".First", function() cat("\n Welcome to R!\n\n"), envir globalenv()) assign(".Last", function() cat("\n Goodbye!\n\n"), envir = globalenv()) [[alternative HTML version deleted]]