Checkout master first

.github/workflows/composite/build_base.yml

@@ -9,6 +9,12 @@ outputs:
 runs:
   using: "composite"
   steps:
+    - name: Checkout code
+        uses: actions/checkout@v3
+        with:
+          submodules: "recursive"
+          ref: ${{github.event.pull_request.head.ref}}
+          repository: ${{github.event.pull_request.head.repo.full_name}}
 
     - name: Setup Python
       uses: actions/setup-python@v4