ci: Test pip failure

.github/workflows/ci.yml

@@ -94,6 +94,15 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: 'recursive'
+      - name: Test Python in container
+        run:
+          which python
+          which pip
+          which python3
+          which pip3
+          python3 --version
+          python3 -m pip --version
+          python3 -m pip install anytree
       - name: Hash Verilator prerequisites
         id: verilator-hash
         uses: colluca/list-make-prerequisites@47dce852f65f327e7b5e440db21067b7c92fa07c