Description of problem:

For over a week now, VirtualBox-guest has dependency errors, so the system cannot be updated, yum update fails in the same way:

$ yum install VirtualBox-guest.x86_64
Loaded plugins: etckeeper, langpacks
Resolving Dependencies
--> Running transaction check
---> Package VirtualBox-guest.x86_64 0:4.3.20-3.fc21 will be installed
--> Processing Dependency: VirtualBox-kmod = 4.3.20 for package: VirtualBox-guest-4.3.20-3.fc21.x86_64
--> Running transaction check
---> Package kmod-VirtualBox.x86_64 0:4.3.20-4.fc21.6 will be installed
--> Processing Dependency: kmod-VirtualBox-3.18.9-200.fc21.x86_64 >= 4.3.20-4.fc21.6 for package: kmod-VirtualBox-4.3.20-4.fc21.6.x86_64
--> Running transaction check
---> Package kmod-VirtualBox-3.18.9-200.fc21.x86_64.x86_64 0:4.3.20-4.fc21.6 will be installed
--> Processing Dependency: kernel-uname-r = 3.18.9-200.fc21.x86_64 for package: kmod-VirtualBox-3.18.9-200.fc21.x86_64-4.3.20-4.fc21.6.x86_64
--> Finished Dependency Resolution
Error: Package: kmod-VirtualBox-3.18.9-200.fc21.x86_64-4.3.20-4.fc21.6.x86_64 (rpmfusion-free-updates)
           Requires: kernel-uname-r = 3.18.9-200.fc21.x86_64
           Installed: kernel-3.13.9-100.fc19.x86_64 (@updates/19)
               kernel-uname-r = 3.13.9-100.fc19.x86_64
           Installed: kernel-3.14.4-200.fc20.x86_64 (installed)
               kernel-uname-r = 3.14.4-200.fc20.x86_64
           Installed: kernel-3.17.8-200.fc20.x86_64 (@updates/20)
               kernel-uname-r = 3.17.8-200.fc20.x86_64
           Installed: kernel-core-3.18.3-201.fc21.x86_64 (installed)
               kernel-uname-r = 3.18.3-201.fc21.x86_64
           Available: kernel-core-3.17.4-301.fc21.x86_64 (fedora)
               kernel-uname-r = 3.17.4-301.fc21.x86_64
           Available: kernel-core-3.19.1-201.fc21.x86_64 (updates)
               kernel-uname-r = 3.19.1-201.fc21.x86_64
           Available: kernel-debug-core-3.17.4-301.fc21.x86_64 (fedora)
               kernel-uname-r = 3.17.4-301.fc21.x86_64+debug
           Available: kernel-debug-core-3.19.1-201.fc21.x86_64 (updates)
               kernel-uname-r = 3.19.1-201.fc21.x86_64+debug
 You could try using --skip-broken to work around the problem
** Found 1 pre-existing rpmdb problem(s), 'yum check' output follows:
nautilus-actions-3.2.2-4.fc20.x86_64 has missing requires of libgtop-2.0.so.7()(64bit)
$ yum list VirtualBox-guest.x86_64
Loaded plugins: etckeeper, langpacks
Available Packages
VirtualBox-guest.x86_64           4.3.20-3.fc21           rpmfusion-free-updates



Version-Release number of selected component (if applicable):

Fedora 21 with kernel 3.18.3-201.fc21.x86_64.



How reproducible:

Everytime.



Steps to Reproduce:
1. yum upgrade or yum install VirtualBox-guest



Actual results:

Fails.



Expected results:

Should work.



Additional info:

Has worked before (same config).