summary fix

Author: maureeungaro

.github/workflows/docker.yml

@@ -103,14 +103,25 @@ jobs:
 
 
       - name: Summarize image reference
-        if: ${{ always() }}
+        shell: bash
         env:
           IMAGE: ${{ needs.discover.outputs.image }}
           TAG: ${{ matrix.geant4_tag }}-${{ matrix.docker_from }}
           PUSHED: ${{ github.event_name != 'pull_request' }}
           IS_ARCH: ${{ startsWith(matrix.docker_from, 'archlinux:') }}
         run: |
+          # prepare summary target safely
+          if [ -n "${GITHUB_STEP_SUMMARY:-}" ]; then
+            mkdir -p "$(dirname "$GITHUB_STEP_SUMMARY")"
+            SUMMARY_OUT="$GITHUB_STEP_SUMMARY"
+          else
+            SUMMARY_OUT="$RUNNER_TEMP/step_summary.md"
+            mkdir -p "$(dirname "$SUMMARY_OUT")"
+            echo "GITHUB_STEP_SUMMARY not set; writing to $SUMMARY_OUT"
+          fi
+      
           PLATFORM_HINT="--platform=linux/amd64"
+      
           {
             echo "## Docker Image"
             echo ""
@@ -142,19 +153,18 @@ jobs:
 
             echo ""
             echo "### Run with browser (noVNC)"
-            echo "This container exposes a VNC-over-WebSocket UI on port **6080**. After starting, open **http://localhost:6080** in your browser."
+            echo "Open **http://localhost:6080** after starting."
             echo ""
             echo "**Default geometry:** \`1280x800\` (override with \`-e GEOMETRY=WIDTHxHEIGHT\`)."
             echo ""
-            echo '**Start (Linux/Windows, same host arch):**'
+            echo '**Start (same-arch host):**'
             echo '```bash'
             if [ "$IS_ARCH" = "true" ]; then
               echo "docker run --rm -p 6080:6080 ${PLATFORM_HINT} ${IMAGE}:${TAG}"
             else
               echo "docker run --rm -p 6080:6080 ${IMAGE}:${TAG}"
             fi
             echo '```'
-      
             echo ""
             echo '**Start with custom resolution:**'
             echo '```bash'
@@ -165,14 +175,10 @@ jobs:
             fi
             echo '```'
 
-            echo ""
-            echo '**Start on Apple Silicon (Mac, Arch image is amd64-only):**'
-            echo '```bash'
-            echo "docker run --rm -p 6080:6080 ${PLATFORM_HINT} ${IMAGE}:${TAG}"
-            echo '```'
-      
             echo ""
             echo "### Notes by distro"
-            echo "- **Ubuntu/Debian/Fedora/AlmaLinux**: container launches **Xvfb + x11vnc + noVNC**; browse to http://localhost:6080."
-            echo "- **Arch Linux**: container launches **Xvfb + x0vncserver (TigerVNC) + noVNC**; image is amd64-only → use \`${PLATFORM_HINT}\` on arm64 hosts."
-          } >> \"$GITHUB_STEP_SUMMARY\"
+            echo "- **Ubuntu/Debian/Fedora/AlmaLinux**: Xvfb + x11vnc + packaged noVNC."
+            echo "- **Arch Linux**: Xvfb + x0vncserver (TigerVNC) + noVNC from /opt (amd64-only → use \`${PLATFORM_HINT}\` on arm64)."
+          } >> "$SUMMARY_OUT"
+      
+          echo "Summary written to: $SUMMARY_OUT"