diff --git a/.github/workflows/f2-3-ci.yml b/.github/workflows/f2-3-ci.yml
index 099a394..abd70fe 100644
--- a/.github/workflows/f2-3-ci.yml
+++ b/.github/workflows/f2-3-ci.yml
@@ -51,4 +51,12 @@ jobs:
           if-no-files-found: warn
           retention-days: 3
       - name: Build
-        run: npm run build
+        run: npm run build 2>&1 | tee build.log
+      - name: Upload build diagnostic
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: f2-3-build-diagnostic
+          path: api-v3/build.log
+          if-no-files-found: warn
+          retention-days: 3