Fix saving package cache on Windows & older R (#944)

* Empty commit to trigger a GHA run

* Add interactive debugging

Temporarily for now.

* setup-r-dependencies: set path to avoid Rtools tar & zstd

* setup-r-dependencies: do not prioritize c:/windows/system32 path

Makes setup-quarto fail (?!).

* setup-r-dependencies: add back the tar path change for R 3.x

Probably still needed.

* Remove debug-shell

* Update NEWS

NEWS.md

@@ -21,6 +21,9 @@
 * `[setup-renv]` now correctly accepts `bypass-cache: never`, as stated
   in the documentation.
 
+* `[setup-r-dependencies]` now saves the package cache correctly on
+  Windows with older R (#940).
+
 # `v2.10.1` (2024-08-08)
 
 * `[setup-r-dependencies]` now pins `quarto-dev/quarto-actions/setup`

setup-r-dependencies/action.yaml

@@ -174,6 +174,12 @@ runs:
         shell: Rscript {0}
         working-directory: ${{ inputs.working-directory }}
 
+      - name: Adjust PATH to avoid using zstd from Rtools
+        if: runner.os == 'Windows'
+        shell: bash
+        run: |
+          echo 'C:/tools/zstd' >> $GITHUB_PATH
+
       - name: R package cache
         if: inputs.cache == 'true'
         uses: actions/cache@v4