Merge pull request #1658 from rstudio/bugfix/positron-windows-subprocess

Patch `subprocess.Popen` when running on Windows under Positron

NEWS.md

@@ -32,13 +32,17 @@
 
 - `as.character()` method for `python.builtin.bytes` gains a `nul` argument,
   allowing for convenient handling of embedded NULs in the string. (#1652)
-  
+
 - 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)
 
+- Fixed an error where opening a Python subprocess in Positron on Windows
+  resulted in "OSError: [WinError 6] The handle is invalid."
+  (#1658, posit-dev/positron#4457)
+
 # reticulate 1.38.0
 
 - Python Exceptions converted to R conditions are now R lists instead

R/config.R

@@ -1005,6 +1005,10 @@ is_rstudio_desktop <- function() {
   identical(version$mode, "desktop")
 }
 
+is_positron <- function() {
+  exists(".ps.ark.version", envir = globalenv())
+}
+
 clean_version <- function(version) {
   gsub("\\.$", "", gsub("[A-Za-z_+].*$", "", version))
 }

R/package.R

@@ -63,7 +63,7 @@ ensure_python_initialized <- function(required_module = NULL) {
   remap_output_streams()
   set_knitr_python_stdout_hook()
 
-  if (is_windows() && identical(.Platform$GUI, "RStudio"))
+  if (is_windows() && ( is_rstudio() || is_positron() ))
     import("rpytools.subprocess")$patch_subprocess_Popen()
 
   # generate 'R' helper object

R/repl.R

@@ -92,7 +92,7 @@ repl_python <- function(
 
   ensure_python_initialized()
   if (is.null(input) &&
-      Sys.getenv("POSITRON") == "1" &&
+      is_positron() &&
       exists(".ps.reticulate_open", inherits = TRUE)) {
 
     eval(call(".ps.reticulate_open"))