prep for matrix

Author: jeroen

.github/workflows/build.yml

@@ -153,7 +153,11 @@ jobs:
     if: ${{ always() && needs.source.outputs.sourcepkg }}
     runs-on: ubuntu-22.04
     timeout-minutes: 60
-    name: Build for webassembly
+    name: Build R-${{ matrix.r }} for WASM
+    strategy:
+      fail-fast: false
+      matrix:
+        r: [ 'oldrel' 'release' ]
     steps:
 #      - name: "Restore package library"
 #        uses: actions/cache/restore@v4
@@ -167,8 +171,9 @@ jobs:
           name: package-source
           path: .
       - id: build
+        if: ${{ matrix.r == 'oldrel' }}
         name: Build wasm binary
-        uses: r-universe-org/build-wasm@master
+        uses: r-universe-org/build-wasm@oldrel
         with:
           sourcepkg: ${{ needs.source.outputs.sourcepkg }}
         env: