to silence the warning like follow the suggestion from pip ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts. We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default. Fixes: https://tracker.ceph.com/issues/47636 Signed-off-by: Kefu Chai <kchai@redhat.com>