ci: try with findmnt for even more

Author: cpcloud

.github/workflows/test-wheel-linux.yml

@@ -96,6 +96,11 @@ jobs:
       - name: Checkout ${{ github.event.repository.name }}
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8  # v5.0.0
 
+      - name: show the mount of the testing dir
+        run: |
+          findmnt --target="$PWD"
+          exit 1
+
       - name: Setup proxy cache
         uses: nv-gha-runners/setup-proxy-cache@main
         continue-on-error: true