Feature request: check for multiple .Renviron files and throw a warning if found

[jmb01]

It has been noted (e.g., here) that on Windows it is possible for R and RStudio to check for .Renviron in different places, causing confusion when changes are made via edit_r_environ() and then don't take effect upon restart.

It would be helpful to check for the presence of .Renviron in both locations and to throw a warning if a version is found in a location other than the one being edited.

[jennybc]

I'm sort of skeptical of this:

on Windows it is possible for R and RStudio to check for .Renviron in different places

In particular, I'm doubtful RStudio has anything to do with it. Locating and loading .Renviron should be just an R matter, regardless of whether the R session is associated with RStudio or not.

But it is true that R's notion of the user's home directory on Windows is kind of confusing and regrettable. This situation is described in the docs for fs::path_home_r():

https://fs.r-lib.org/reference/path_expand.html

I suspect that whatever problem inspired this issue is more likely to have that situation as its root cause.

But I'm also not sure exactly what the ask for usethis is, i.e. usethis doesn't so any sort of "health check" of this sort of thing, especially unsolicited. AFAIK usethis itself is careful to build the correct path for .Renviron, including on Windows.