Bug 1776795

Description of problem:
It is not possible to upgrade newt without any additional flags to dnf
--best --allowerasing. But using --allowerasing in automated scripts is dangerous.


Version-Release number of selected component (if applicable):
newt-0.52.21-5.fc32.x86_64

How reproducible:
Deterministic

Steps to Reproduce:
  // install package python2-newt (we will use f31 container image but you can do that on rawhide from koji)
1. docker run -ti --rm docker.io/fedora:31 bash
   //run rest of commands in container
2. dnf install -y python2-newt fedora-repos-rawhide
3. dnf --disablerepo=* --enablerepo=rawhide update -y newt

Actual results:
[root@5ce4d1240279 /]# dnf --disablerepo=* --enablerepo=rawhide update -y libxml2
Last metadata expiration check: 0:00:41 ago on Tue Nov 26 11:44:23 2019.
Dependencies resolved.

 Problem: cannot install both libxml2-2.9.10-1.fc32.x86_64 and libxml2-2.9.10-1.fc31.x86_64
  - package python2-libxml2-2.9.10-1.fc31.x86_64 requires libxml2(x86-64) = 2.9.10-1.fc31, but none of the providers can be installed
  - cannot install the best update candidate for package libxml2-2.9.10-1.fc31.x86_64
  - problem with installed package python2-libxml2-2.9.10-1.fc31.x86_64
================================================================================
 Package          Architecture    Version                Repository        Size
================================================================================
Skipping packages with conflicts:
(add '--best --allowerasing' to command line to force their upgrade):
 libxml2          x86_64          2.9.10-1.fc32          rawhide          693 k

Transaction Summary
================================================================================
Skip  1 Package

Nothing to do.
Complete!


Expected results:
The package is upgraded without any problem

Additional info:
temporary workaround: dnf remove -y python2-newt
But it does not scale if you have to maintain updates on many machines.