Don't use shutil backport on py3
Review Request #10047 — Created June 29, 2018 and updated — Latest diff uploaded
On many distributions (including Fedora and RHEL 7), the backports.shutil package doesn't exist for python 3.x because it's meaningless. Instead of unconditionally including it, use the appropriate import for the python version in use.
Submitted this very review using
rbt poston python3 with this patch applied.