do check out for the workflow

Jonathan Kliem · Jonathan Kliem · commit 1c94b8603fca · 2021-10-14T23:02:43.000+02:00
diff --git a/.github/workflows/build_wheels.yml b/.github/workflows/build_wheels.yml
@@ -15,6 +15,8 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
+      - uses: actions/checkout@v2
+
       - name: Build wheels
         uses: pypa/cibuildwheel@v2.1.3
         # to supply options, put them in 'env', like:
