Leapp upgrade fails due to file conflicts between RHEL 8 python39-* packages and RHEL 9 python3-* packages

Issue

• The Leapp in-place upgrade from RHEL 8 to RHEL 9 fails with the following error message:

  Following errors occurred and the upgrade cannot continue:
      1. Actor: dnf_package_download
         Message: DNF execution failed with non zero exit code.
  

  $ grep conflict var/log/leapp/leapp-upgrade.log | head -5
  2026-04-06 10:42:26.593 DEBUG    PID: 60709 leapp.workflow.Download.dnf_package_download:   file /usr/lib/python3.9/site-packages/resolvelib/__pycache__/structs.cpython-39.opt-1.pyc from install of python3-resolvelib-0.5.4-5.el9.noarch conflicts with file from package python39-resolvelib-0.5.4-6.el8ap.noarch
  2026-04-06 10:42:26.595 DEBUG    PID: 60709 leapp.workflow.Download.dnf_package_download:   file /usr/lib/python3.9/site-packages/resolvelib/__pycache__/structs.cpython-39.pyc from install of python3-resolvelib-0.5.4-5.el9.noarch conflicts with file from package python39-resolvelib-0.5.4-6.el8ap.noarch
  2026-04-06 10:42:26.597 DEBUG    PID: 60709 leapp.workflow.Download.dnf_package_download:   file /usr/lib/python3.9/site-packages/packaging/__about__.py from install of python3-packaging-20.9-5.el9.noarch conflicts with file from package python39-packaging-21.3-2.el8ap.noarch
  2026-04-06 10:42:26.598 DEBUG    PID: 60709 leapp.workflow.Download.dnf_package_download:   file /usr/lib/python3.9/site-packages/packaging/__init__.py from install of python3-packaging-20.9-5.el9.noarch conflicts with file from package python39-packaging-21.3-2.el8ap.noarch
  2026-04-06 10:42:26.598 DEBUG    PID: 60709 leapp.workflow.Download.dnf_package_download:   file /usr/lib/python3.9/site-packages/packaging/__pycache__/__about__.cpython-39.opt-1.pyc from install of python3-packaging-20.9-5.el9.noarch conflicts with file from package python39-packaging-21.3-2.el8ap.noarch