"ERROR: Can not execute `setup.py` since setuptools is not available in "
  ERROR: Failed building wheel for internal-testcpp03ext
ERROR: ERROR: Failed to build installable wheels for some pyproject.toml based projects (internal-testcpp03ext)
ERROR: test_build_cpp03 (test.test_cppext.TestCPPExt.test_build_cpp03)
Re-running test_cppext in verbose mode (matching: test_build_cpp03)
          "ERROR: Can not execute `setup.py` since setuptools is not available in "
  ERROR: Failed building wheel for internal-testcpp03ext
ERROR: ERROR: Failed to build installable wheels for some pyproject.toml based projects (internal-testcpp03ext)
ERROR: test_build_cpp03 (test.test_cppext.TestCPPExt.test_build_cpp03)