UKUU 21.05

Ubuntu Kernel Update Utility v21.05 is now available.

What’s New

Dependency Changes

Last week, Ubuntu updated the dependencies required by the mainline kernel packages. The linux-header-generic package now has a minimum requirement of libc6 v2.33. This version is available only on Ubuntu 21.04 (Hirsute Hippo) that was released recently. Due to this dependency change, the header packages can no longer be installed on older releases of Ubuntu.

libc6 is a low-level system library. Almost every package on your system depends on it. Upgrading this library to v2.33 is next to impossible without also upgrading other low-level libraries on your system. If you are willing to do that, then you might as well switch to Ubuntu 21.04.

Since a majority of users are still on the current LTS (Ubuntu 20.04) a work-around has been added to UKUU v21.05. The app will allow you to install the newer mainline kernels on older versions of Ubuntu.

Keep in mind that installing a newer kernel on an older system is not recommended. Install the mainline kernels on older releases of Ubuntu at your own risk. The mainline kernels are not meant for production use and can cause problems with hardware that require proprietary drivers (NVIDIA graphics, VirtualBox, Broadcomm WiFi, etc).

You can always boot an older kernel from the GRUB boot menu in case of any problem. This is quite easy to do. Hold down SHIFT while your system boots and select an older kernel from GRUB Menu > “Advanced options for Ubuntu”.

Once the system has booted the old kernel, uninstall the new one that is causing problems.

If you use Refind instead of GRUB then the steps are similar. Select the OS from the boot screen and press Insert to show the list of available kernels.

Select and boot older kernel from Refind boot menu

Optimised Packages

Packages for UKUU are now optimized for each distribution that it runs on. So instead of a single repository and a single set of packages, there are now different repositories for different releases of Ubuntu. You need to re-run the installation command for UKUU to switch to the newer repository.

New Icon

The app icon received a redesign. This change was long overdue.

Install / Update

If you are an existing user, please re-run the installation command to add the new repository and update to the latest version. Installation steps are the same as before. Please refer to the email you received at the time of purchase.


A single-user license for UKUU can be purchased from the link below:

This Post Has 14 Comments

  1. Mike L

    Just saying thanks for this tool.

    I don’t install the mainline kernels, but it’s nice to see what’s possible. And also thanks for the very informative update notice so I know that I particularly don’t want to install a new kernel on my 20.04 system.

    I use UKUU mostly to see and clean up the kernels that are installed. I’ve learned enough that I can now do that myself w/ apt, but UKUU makes it easier.

    I’m quite happy I bought a lifetime license.

    1. Tony George

      Thanks for your support. There is no need to use mainline kernels unless there is some new feature that you want to use. The normal Ubuntu kernels work perfectly fine.

  2. RandomChain

    Thanks for the update. I like the new icon.

    What about support for systemd-boot? Is this on you roadmap?

    1. Tony George

      There is nothing special required for systemd-boot. UKUU and mainline kernels already work on PopOS. Are you facing any specific issues?

      1. RandomChain

        A somewhat delayed response… recently I tried installing a different kernel on Pop!_OS 20.04 and remembered what bothered me. My main issue is that UKUU will automatically install and configure GRUB, and I could not find a way to disable that. With kernelstub on Pop!_OS, it is set to run after kernel installation and GRUB isn’t needed at all.

        I would also be happy to see an option to configure a new kernel on systemd-boot via UKUU, that is copy to /boot/efi/EFI and set the conf file in /boot/efi/loader – basically what kernelstub does, but kernelstub only support 2 kernels from the same “line” so I just keep it managing the Pop!_OS stock kernels and set up manually if I want a Mainline kernel too. I suppose this is a pretty big new feature but it would be nice if you can make it work some day.

        1. Tony George

          systemd-boot lacks a lot of features. Try installing Refind boot manager. It is similar to systemd-boot but with much more features. If you select an OS and press INSERT key it displays all installed kernels. No configuration is needed.

  3. Josef Fröhle

    I’m not able to install new kernels. I get allways an error: Packages are missing in PPA for this kernel version (arch=amd64, flavor=generic)

    nerver had before this problem

    1. Tony George

      The kernels are provided by Ubuntu on their mainline kernel server.

      If packages are missing on the server then you will get this error till someone from the Ubuntu team fixes the issue and rebuilds the packages. Which version are you trying to install?

  4. Alexander

    UKUU is great! You could consider building it into something that allowed for kernel bisection, helping people with more easily identifying which commits were the troublesome ones.

  5. Clay

    Do you have a version for 21.1 I’m getting an error —

    Some packages could not be installed. This may mean that you have
    requested an impossible situation or if you are using the unstable
    distribution that some required packages have not yet been created
    or been moved out of Incoming.
    The following information may help to resolve the situation:

    The following packages have unmet dependencies:
    linux-headers-5.15.7-051507-generic : Depends: libssl3 (>= 3.0.0~~alpha1) but it is not installable
    E: Unable to correct problems, you have held broken packages.

    1. Tony George

      The 5.15.7 kernel seems to be built against libssl3 which is not available in Ubuntu repositories. This may be in preparation for adding libssl3 in Ubuntu 22.04. You can install the libssl3 package manually if you can find it on the internet. I’m searching for a solution.

    2. Tony George

      Libssl3 is added to the UKUU repository. Install it with the following commands, and then try installing the kernel.

      sudo apt update
      sudo apt install libssl3

  6. Daniel Albright

    I’m a fan of this utility. It does exactly what I want it to do, and it’s easy as pie to use. Good job, sir!

    I have a question for you. Why does kernel 5.15 not show that it is LTS?

    1. Tony George

      The LTS status needs to be manually updated in the app. I’ll update it.

Comments are closed.