Just a note for everyone/anyone who installed Fedora 22 from anything before the Release Candidate (RC) composes: (If you install from the final release on tuesday you are not affected of course):
Before this point the updates-testing repository was enabled and you very likely installed some things from it if you did any installs or updates after you installed. A fedora-release update came along and disabled this repo now, so you have packages from it installed, but that repo is no longer enabled. This can show up as weird issues around mismatched devel packages or other strange looking dependency issues.
Please do one of the following if you see any such issues:
1. You can re-enable updates-testing and help us test updates. See: https://fedoraproject.org/wiki/How_to_test_updates
2. You can run a ‘dnf distro-sync’ and downgrade your packages to all the correct versions available in updates and the base repo.