I ran "sudo dnf system-upgrade --releasever=23 --allowerasing" (I'm currently on F22).

At the end, after all the downloading, it reported:

Running transaction check
Transaction check succeeded.
Running transaction test
The downloaded packages were saved in cache till the next successful transaction.
You can remove cached packages by executing 'dnf clean packages'.
Error: Transaction check error:
  file /usr/bin from install of filesystem-3.2-35.fc23.x86_64 conflicts with file from package google-earth-stable-6.0.3.2197-0.x86_64

I then tried to do the upgrade, but it failed because apparently it didn't like the conflict shown above:

$ sudo dnf system-upgrade reboot
Error: system is not ready for upgrade
$ 

So I erased google-search-stable with "sudo dnf remove google-earth-stable", then ran the original command, "sudo dnf system-upgrade download --allowerasing --releasever=23" again, to make sure I was ready.

It proceeded to download all 6,103 packages over again, because apparently either running "sudo dnf system-upgrade reboot" when it wasn't ready or "sudo dnf remove google-earth-stable" told dnf that it was a good idea to delete everything in /var/lib/dnf/system-upgrade.

This is monumentally stupid.