https://github.com/actions/checkout/issues/766

.github/workflows/update-calendar.yml

@@ -23,6 +23,7 @@ jobs:
         Rscript ecb.R
     - name: Commit and push if it changed
       run: |-
+        git config --global --add safe.directory "$GITHUB_WORKSPACE"
         git config user.name "Automatic"
         git config user.email "actions@users.noreply.github.com"
         git add *.ics