diff --git a/.github/workflows/build_and_deploy.yml b/.github/workflows/build_and_deploy.yml
index 6cd10ed..244c8f8 100644
--- a/.github/workflows/build_and_deploy.yml
+++ b/.github/workflows/build_and_deploy.yml
@@ -57,8 +57,6 @@ jobs:
         if: steps.cache.outputs.cache-hit != 'true'
         run: |
           apt-get update -qq && apt-get install -y -qq make
-          # running as root: mark the checkout safe so the data.json commit stamp works
-          git config --global --add safe.directory "$GITHUB_WORKSPACE"
           sage -pip install --quiet --no-cache-dir pandas seaborn
           make sweeps derived data figures PYTHON="sage -python"
 
diff --git a/export_site_data.sage b/export_site_data.sage
index 0087cf2..c3d03d4 100644
--- a/export_site_data.sage
+++ b/export_site_data.sage
@@ -204,7 +204,8 @@ def _commit():
             ['git', 'rev-parse', '--short', 'HEAD'],
             cwd=_dir, stderr=subprocess.DEVNULL).decode().strip()
     except Exception:
-        return 'unknown'
+        sha = os.environ.get('GITHUB_SHA', '')
+        return sha[:7] if sha else 'unknown'
 
 
 data = {