system-upgrade from F27 to F28 downgrades packages

[Martín Marqués]

Hi,

I'm trying to upgrade one of my machines at home from F27 to F28 using `dnf
system-upgrade` which is failing with errors related with GPG Key signature
failure for certain packages. Investigating I see that all those packages
are to be "downgraded" for some reason:

Downgrading:
 hplip                                x86_64
3.18.3-1.fc28                     fedora            16 M
 hplip-common                         x86_64
3.18.3-1.fc28                     fedora           108 k
 hplip-libs                           x86_64
3.18.3-1.fc28                     fedora           202 k
 libuv                                x86_64
1:1.23.0-1.fc28                   updates          133 k
 open-vm-tools                        x86_64
10.3.0-4.fc28                     updates          696 k
 open-vm-tools-desktop                x86_64
10.3.0-4.fc28                     updates          182 k
 pgbouncer                            x86_64
1.9.0-1.f28.1                     pgdg11           176 k
 pgbouncer-debuginfo                  x86_64
1.9.0-1.f28                       pgdg10-debuginfo 338 k
 python2-attrs                        noarch
17.4.0-2.fc28                     fedora            51 k
 python2-jinja2                       noarch
2.10-2.fc28                       fedora           531 k
 python3-jinja2                       noarch
2.10-2.fc28                       fedora           534 k
 python3-psycopg2                     x86_64
2.7.4-1.fc28                      fedora           170 k

That seems weird, as I have an F28 system running on my laptop and it has
newer versions than the ones there for all those packages

Also, the packages downloaded seem to be signed with a different Key giving
errors like the following:

 GPG Keys are configured as:
file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-27-x86_64
Public key for zstd-1.3.6-1.fc28.x86_64.rpm is not installed. Failing
package is: zstd-1.3.6-1.fc28.x8
6_64
 GPG Keys are configured as:
file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-27-x86_64
Public key for zziplib-0.13.69-1.fc28.x86_64.rpm is not installed. Failing
package is: zziplib-0.13.69
-1.fc28.x86_64
 GPG Keys are configured as:
file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-27-x86_64
The downloaded packages were saved in cache until the next successful
transaction.
You can remove cached packages by executing 'dnf clean packages'.
Error: GPG check FAILED

Anyway I can fix this without having to reinstall all my system from
scratch?

Regards

-- 
Martín Marqués
It’s not that I have something to hide,
it’s that I have nothing I want you to see