check, knitr - Add .exe to binary on Windows for correct check

news/changelog-1.8.md

@@ -69,6 +69,10 @@ All changes included in 1.8:
 
 - ([#12753](https://github.com/quarto-dev/quarto-cli/issues/12753)): Support change in IPython 9+ and import `set_matplotlib_formats` from `matplotlib_inline.backend_inline` in the internal `setup.py` script used to initialize rendering with Jupyter engine.
 
+### `knitr`
+
+- Correctly detect R binary on Windows when `R_HOME` is set - this fixes issue with `quarto::quarto_render()` that will now correctly use the same R version as the R session it is called from.
+
 ## Other fixes and improvements
 
 - ([#11321](https://github.com/quarto-dev/quarto-cli/issues/11321)): Follow [recommendation from LaTeX project](https://latex-project.org/news/latex2e-news/ltnews40.pdf) and use `lualatex` instead of `xelatex` as the default PDF engine.

src/core/resources.ts

@@ -117,7 +117,7 @@ export async function rBinaryPath(
   const rHome = Deno.env.get("R_HOME");
   debug(`Looking for '${binary}' in R_HOME: ${rHome}`);
   if (rHome) {
-    let rHomeBin = join(rHome, "bin", binary);
+    let rHomeBin = join(rHome, "bin", isWindows ? binary + ".exe" : binary);
     if (safeExistsSync(rHomeBin)) {
       debug(`Found in ${rHomeBin}`);
       return setPath(rHomeBin);