Why does preupg fails with error 'Incorrect usage of reserved UIDs and GIDs'?

Issue

The in-place upgrade (RHEL 6.10 to 7.9) fails because of the following failed rule:

Incorrect usage of reserved UIDs and GIDs

The packages might create system accounts with static IDs based on the reservation in the /usr/share/doc/setup-*/uidgid file. If you have any violations against the uidgid file reservation, the applications might not work properly, or they might cause some unexpected behavior. As the reservations between different releases of Red Hat Enterprise Linux might differ, check the results below carefully.

Especially the cases when an ID reserved by an application is used by a different account are really important. Using a different account than the reserved one might cause interoperability issues.

These issues do not usually cause critical failures, but in rare cases they might contribute to some hard-to-analyze failures in the case where the system ID values are hard-coded in the application.