I'm really confused. I followed the upgrade instructions to get R6.02, which I thought contained myth 0.22:



But did I somehow end up with myth 0.23?



What's going on here? Is there a way to downgrade to the latest stable release?

In your /etc/pacman.conf you must have core-testing and extra-testing uncommented. If you don't want the testing repos in your /etc/pacman.conf comment out core-testing and extra-testing and uncomment or add:
Unless you have a backup of your db prior to upgrading you can't go back down to .22. However, in my experience .23 is much more stable than .22 was.

Yes, that's exactly right. I don't know how it got that way. I need 0.22 so that it will work with the available frontend package on my ubuntu desktop. Fortunately I did make a backup before the upgrade.