Merge pull request #1657 from rstudio/virtualenv-root-env-var

Support `RETICULATE_VIRTUALENV_ROOT` env var

NEWS.md

@@ -35,6 +35,9 @@
 
 - New `as.character()` method for `python.builtin.str` with support for handling
   embedded NULs in strings. (#1653)
+
+- Reticulate will now use the `RETICULATE_VIRTUALENV_ROOT` environment variable 
+  when determining where to resolve virtual environments. (#1657)
 
 # reticulate 1.38.0
 

R/virtualenv.R

@@ -5,7 +5,7 @@
 #'
 #' Virtual environments are by default located at `~/.virtualenvs` (accessed
 #' with the `virtualenv_root()` function). You can change the default location
-#' by defining the `WORKON_HOME` environment variable.
+#' by defining the `RETICULATE_VIRTUALENV_ROOT` or `WORKON_HOME` environment variables.
 #'
 #' Virtual environments are created from another "starter" or "seed" Python
 #' already installed on the system. Suitable Pythons installed on the system are
@@ -333,6 +333,10 @@ virtualenv_list <- function() {
 #' @rdname virtualenv-tools
 #' @export
 virtualenv_root <- function() {
+  root <- Sys.getenv("RETICULATE_VIRTUALENV_ROOT", NA_character_)
+  if (!is.na(root))
+    return(root)
+
   Sys.getenv("WORKON_HOME", unset = "~/.virtualenvs")
 }