Description of problem:

I got an error involving libvirt-daemon-driver-storage-rbd while running dnf system-upgrade from F29 to F30.

Problem 1: package libvirt-daemon-driver-storage-rbd-4.7.0-1.fc29.i686 requires libvirt-daemon-driver-storage-core = 4.7.0-1.fc29, but none of the providers can be installed
  - libvirt-daemon-driver-storage-core-4.7.0-1.fc29.i686 does not belong to a distupgrade repository
  - problem with installed package libvirt-daemon-driver-storage-rbd-4.7.0-1.fc29.i686

I have many of the libvirt i686 packages installed. 

sudo dnf system-upgrade download --refresh --releasever=30 --skip-broken --allowerasing showed libvirt-daemon-driver-storage-rbd being removed:

Removing dependent packages:
...
libvirt-daemon-driver-storage-rbd i686   4.7.0-1.fc29   @updates-testing 108 k

Version-Release number of selected component (if applicable):
libvirt-daemon-driver-storage-rbd-4.7.0-1.fc29.i686
libvirt-5.1.0-1.fc30.i686

How reproducible:
5 of 5 times

Steps to Reproduce:
In F29 with updates-testing enabled and libvirt-daemon-driver-storage-rbd-4.7.0-1.fc29.i686 installed
1. sudo dnf upgrade --refresh
2. sudo dnf system-upgrade download --refresh --releasever=30
3. sudo dnf system-upgrade download --refresh --releasever=30 --skip-broken --allowerasing

Actual results:
dnf system-upgrade error involving libvirt-daemon-driver-storage-rbd-4.7.0-1.fc29.i686

Expected results:
no error

Additional info:

libvirt-5.1.0-1.fc30's changelog on koji noted the following. 
* Mon Dec 10 2018 Daniel P. Berrangé <berrange> - 4.10.0-2 
- Disable RBD on 32-bit arches (rhbz #1657928)

https://koji.fedoraproject.org/koji/buildinfo?buildID=1219635

Obsoleting libvirt-daemon-driver-storage-rbd on 32-bit architectures might prevent this error if it isn't going to be built again for them. This issue is likely related to the qemu-block-rbd error I reported in bug 1688117.