Dnf update fails with: cannot install the best update candidate for package kernel-devel-matched-5.14.0-570.42.2.el9_6.x86_64

Hi All -

I was updating my system today and encountered this error:

[chad@optiplex-mini ~]$ sudo dnf update
Last metadata expiration check: 2:41:37 ago on Fri 10 Oct 2025 09:42:32 AM EDT.
Error: 
 Problem: cannot install the best update candidate for package kernel-devel-matched-5.14.0-570.42.2.el9_6.x86_64
  - nothing provides kernel-core = 5.14.0-570.49.1.el9_6 needed by kernel-devel-matched-5.14.0-570.49.1.el9_6.x86_64 from appstream
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)
[chad@optiplex-mini ~]$ 

Does anyone know if perhaps this is just some transient issue because something hasn’t been updated on the Appstream repo yet (like kernel-core)?

I was trying to remember what I was doing and what I changed to add the kernel-devel packages in the past - and I think I was trying to compile some video encoder so I could play videos that I download from my Alfred Camera recordings. Anyhow - from my logs on 08/18 I was able to install dkms and kernel-devel:

/var/log/dnf.log.3:2025-08-18T22:29:04-0400 DDEBUG Command: dnf install dkms kernel-devel 
/var/log/dnf.log.3:2025-08-18T22:29:04-0400 DDEBUG Extra commands: ['install', 'dkms', 'kernel-devel']
/var/log/dnf.log.3:2025-08-18T22:29:05-0400 INFO Package kernel-devel-5.14.0-503.40.1.el9_5.x86_64 is already installed.
/var/log/dnf.log.3:2025-08-18T22:29:05-0400 INFO Package kernel-devel-5.14.0-570.23.1.el9_6.x86_64 is already installed.
/var/log/dnf.log.3:2025-08-18T22:29:05-0400 INFO Package kernel-devel-5.14.0-570.32.1.el9_6.x86_64 is already installed.
/var/log/dnf.log.3:2025-08-18T22:29:05-0400 DEBUG ---> Package kernel-devel-matched.x86_64 5.14.0-570.32.1.el9_6 will be installed
/var/log/dnf.log.3: kernel-devel-matched                   x86_64                   5.14.0-570.32.1.el9_6                   appstream                   1.8 M
/var/log/dnf.log.3:2025-08-18T22:29:40-0400 DEBUG ---> Package kernel-devel-matched.x86_64 5.14.0-570.32.1.el9_6 will be installed
/var/log/dnf.log.3: kernel-devel-matched                   x86_64                   5.14.0-570.32.1.el9_6                   appstream                   1.8 M
/var/log/dnf.log.3:2025-08-18T22:29:46-0400 DEBUG Installed: kernel-devel-matched-5.14.0-570.32.1.el9_6.x86_64
/var/log/dnf.log.3:2025-08-18T22:29:46-0400 DDEBUG /var/cache/dnf/appstream-25485261a76941d3/packages/kernel-devel-matched-5.14.0-570.32.1.el9_6.x86_64.rpm removed

And then I was able to update these on 09/30:

[chad@optiplex-mini ~]$ sudo grep kernel-devel /var/log/dnf.log*
/var/log/dnf.log:2025-09-30T15:52:50-0400 DEBUG ---> Package kernel-devel.x86_64 5.14.0-570.42.2.el9_6 will be installed
/var/log/dnf.log:2025-09-30T15:52:50-0400 DEBUG ---> Package kernel-devel-matched.x86_64 5.14.0-570.39.1.el9_6 will be upgraded
/var/log/dnf.log:2025-09-30T15:52:50-0400 DEBUG ---> Package kernel-devel-matched.x86_64 5.14.0-570.42.2.el9_6 will be an upgrade
/var/log/dnf.log:2025-09-30T15:52:50-0400 DEBUG ---> Package kernel-devel.x86_64 5.14.0-570.33.2.el9_6 will be erased
/var/log/dnf.log: kernel-devel                               x86_64          5.14.0-570.42.2.el9_6                appstream                        18 M
/var/log/dnf.log: kernel-devel-matched                       x86_64          5.14.0-570.42.2.el9_6                appstream                       1.8 M
/var/log/dnf.log: kernel-devel                               x86_64          5.14.0-570.33.2.el9_6                @appstream                       70 M
/var/log/dnf.log:2025-09-30T15:58:07-0400 DEBUG Upgraded: kernel-devel-matched-5.14.0-570.42.2.el9_6.x86_64
/var/log/dnf.log:2025-09-30T15:58:07-0400 DEBUG Installed: kernel-devel-5.14.0-570.42.2.el9_6.x86_64
/var/log/dnf.log:2025-09-30T15:58:07-0400 DEBUG Removed: kernel-devel-5.14.0-570.33.2.el9_6.x86_64
/var/log/dnf.log:2025-09-30T15:58:07-0400 DDEBUG /var/cache/dnf/appstream-25485261a76941d3/packages/kernel-devel-matched-5.14.0-570.42.2.el9_6.x86_64.rpm removed
/var/log/dnf.log:2025-09-30T15:58:07-0400 DDEBUG /var/cache/dnf/appstream-25485261a76941d3/packages/kernel-devel-5.14.0-570.42.2.el9_6.x86_64.rpm removed
/var/log/dnf.log: Problem: cannot install the best update candidate for package kernel-devel-matched-5.14.0-570.42.2.el9_6.x86_64
/var/log/dnf.log:  - nothing provides kernel-core = 5.14.0-570.49.1.el9_6 needed by kernel-devel-matched-5.14.0-570.49.1.el9_6.x86_64 from appstream
/var/log/dnf.log: Problem: cannot install the best update candidate for package kernel-devel-matched-5.14.0-570.42.2.el9_6.x86_64

But as you can see today it fails. So I am wondering if something is broken in the app stream repo. Here are my configured repos:

[chad@optiplex-mini ~]$ sudo dnf repolist
[sudo] password for chad: 
repo id                                                                     repo name
appstream                                                                   Rocky Linux 9 - AppStream
baseos                                                                      Rocky Linux 9 - BaseOS
crb                                                                         Rocky Linux 9 - CRB
docker-ce-stable                                                            Docker CE Stable - x86_64
epel                                                                        Extra Packages for Enterprise Linux 9 - x86_64
extras                                                                      Rocky Linux 9 - Extras
google-chrome                                                               google-chrome
rpmfusion-free-updates                                                      RPM Fusion for EL 9 - Free - Updates
rpmfusion-nonfree-updates                                                   RPM Fusion for EL 9 - Nonfree - Updates
slack                                                                       slack
tailscale-stable                                                            Tailscale stable
vivaldi                                                                     vivaldi
[chad@optiplex-mini ~]$ 

chad@optiplex-mini ~]$ sudo dnf list installed | grep -i kernel
kernel.x86_64                                      5.14.0-570.37.1.el9_6               @baseos                
kernel.x86_64                                      5.14.0-570.39.1.el9_6               @baseos                
kernel.x86_64                                      5.14.0-570.42.2.el9_6               @baseos                
kernel-core.x86_64                                 5.14.0-570.37.1.el9_6               @baseos                
kernel-core.x86_64                                 5.14.0-570.39.1.el9_6               @baseos                
kernel-core.x86_64                                 5.14.0-570.42.2.el9_6               @baseos                
kernel-devel.x86_64                                5.14.0-570.37.1.el9_6               @appstream             
kernel-devel.x86_64                                5.14.0-570.39.1.el9_6               @appstream             
kernel-devel.x86_64                                5.14.0-570.42.2.el9_6               @appstream             
kernel-devel-matched.x86_64                        5.14.0-570.42.2.el9_6               @appstream             
kernel-headers.x86_64                              5.14.0-570.42.2.el9_6               @appstream             
kernel-modules.x86_64                              5.14.0-570.37.1.el9_6               @baseos                
kernel-modules.x86_64                              5.14.0-570.39.1.el9_6               @baseos                
kernel-modules.x86_64                              5.14.0-570.42.2.el9_6               @baseos                
kernel-modules-core.x86_64                         5.14.0-570.37.1.el9_6               @baseos                
kernel-modules-core.x86_64                         5.14.0-570.39.1.el9_6               @baseos                
kernel-modules-core.x86_64                         5.14.0-570.42.2.el9_6               @baseos                
kernel-modules-extra.x86_64                        5.14.0-570.37.1.el9_6               @baseos                
kernel-modules-extra.x86_64                        5.14.0-570.39.1.el9_6               @baseos                
kernel-modules-extra.x86_64                        5.14.0-570.42.2.el9_6               @baseos                
kernel-srpm-macros.noarch                          1.0-13.el9                          @appstream             
kernel-tools.x86_64                                5.14.0-570.42.2.el9_6               @baseos                
kernel-tools-libs.x86_64                           5.14.0-570.42.2.el9_6               @baseos                
[chad@optiplex-mini ~]$ 

Probably not a big deal was just curious why this may have recently broken. I imagine if I were to dnf remove dkms and kernel-devel I could get out of this. It also seems a little odd (problematic?) that I would have kernel packages installed from 2 different repositories. It seems to me like this would be some misconfiguration on my part.

Thanks!

I’m going to speculate that the searched repos were not populated / in sync with that kernel update. There have been some sporadic syncing issues with certain repos. So I would try again.

1 Like

As @jbkt23 says, when you experience this, the first thing you should do is:

sudo dnf clean all
sudo dnf update

to refresh your repo data and sync with a reliable mirror. In most situations it will resolve the problem.

1 Like

I just did a dnf clean all and dnf update and all went fine.

Thanks guys.

1 Like