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How to Install COSMIC Desktop on Ubuntu 24.04 (PPA)

If you want to install the new COSMIC desktop on Ubuntu 24.04 LTS, you’re in luck as a new (and totally unofficial) PPA makes it easy — but may upgrade critical system packages in the process.

Chances are you’re familiar with COSMIC, the new, open-source Rust-based desktop environment developed by Linux hardware company System76. It’s a promising modern and configurable alternative to established desktops like GNOME.

COSMIC saw its first stable release earlier this month and is the default desktop in Pop!_OS 24.04 LTS. It is attracting a lot of attention by virtue of being new, and also for being pretty impressive already.

This new community-maintained PPA lets you find out first hand if the reality matches the hype, without needing to jump ship to a new distro.

However, as this is an unofficial third-party repository of packages using it is not without risks.

The primary caveat? The PPA, which is maintained by a community developer called hepp3n, packages more than just COSMIC desktop and apps. It also includes packages to satisfy the requirements of the COSMIC codebase:

• Mesa graphics drivers
• Wayland (and Xwayland)
• llvm-toolchain-20
• Rust compiler

Those are pretty critical system packages you wouldn’t normally want to mess around upgrading (since the rest of the distro depends on them).

However, when I tested this PPA for this post none of these these third-party replacements got installed (clean Ubuntu 24.04.3 LTS install). That could change, of course.

Packages in the Ubuntu repos offer reliability due to amount of testing they get, and the timely fixes and security patches they receive from Canonical.

Adding a 3rd-party PPA which may upgrade system packages won’t necessarily break Ubuntu, but it does break the value of an LTS (and leaves you more vulnerable to security issues and increases the chance of package conflicts during future system updates).

The maintainer of the PPA puts this in their disclaimer: “This is unofficial PPA so you installing it on your own risk,” but adds (all sic) “I am using it and testing so it basically works but keep in mind, everything may happened.”

Installing COSMIC on Ubuntu

The only hard requirement for using hepp3n’s COSMIC Epoch PPA is to be using Ubuntu 24.04 LTS. It can be the desktop edition, server, or a different flavour entirely. So long as the repo base is noble, you can make use of this PPA (and its risks).

Thought it will help to be using hardware that works well with Wayland since COMSIC is a Wayland-only desktop environment.

Before going further do make a system backup, or choose to test it in a VM. At the least, make sure you’re comfortable managing potential package conflicts that might arise (I do cover how to ‘undo’ the package changes further down, be swot up first).

You can use this PPA to install COSMIC desktop on any Linux distribution based on Ubuntu 24.04 LTS, such as Linux Mint 22.x, Zorin OS 18 or elementary OS 8.x.

First, open your terminal and run this command to add the PPA to your system:

sudo add-apt-repository ppa:hepp3n/cosmic-epoch

On Ubuntu, adding a PPA will automatically trigger a system update to refresh the list of packages your system can see. If this doesn’t happen, run sudo apt update before continuing.

Now, install the COMSIC desktop session.

If you are reading this guide from a regular Ubuntu 24.04 install (i.e., with GNOME), run:

sudo apt install cosmic-session

Alternatively, if you’re on Ubuntu Server 24.04 LTS, a flavour or a downstream spin like Linux Mint, run:

sudo apt install --no-install-recommends cosmic-session

Why this command? The PPA maintainer says this is needed to avoid pulling in “unnecessary GNOME-related dependencies” that the core COSMIC packages might otherwise suggest — or, indeed, rely on (so keep that in mind).

During installation you should be prompted to pick which login screen you wish use. You can choose to use the COSMIC Greeter, but if you plan on switching between different desktops, stick with whatever your distro defaults to.

On regular Ubuntu, you must stick with GDM3 if you plan to continue logging into GNOME as the desktop environment is designed for/expects GDM to be present.

Once done, log out and select the cog icon in the lower-right corner (if using GDM), choose the COSMIC desktop session and log back in.

Using COSMIC on Ubuntu

After you log and the COSMIC desktop has loaded you can begin exploring. This isn’t a guide to using COSMIC per se, but as it’s a fairly logical desktop environment (and it is incredibly customisable) a lot of the fun comes from exploring it — words are boring.

But having tested this, there are a few things I’ll point out.

All of your Ubuntu apps and files are still accessible from the COSMIC session (and vice versa; you’ll see app icons for COSMIC apps in your other desktop sessions).

Most, but not all, of the first-party COSMIC apps are present. This includes Files, Term, Text Editor, Screenshot. The video/music player is missing, as is the (rather nice) COSMIC Store (but as it handles DEB system updates it might interfere with distro package management).

You will see a row of blank/missing icons in the COSMIC panel when running this on Ubuntu. These are housed in the desktop’s App Indicator applet (including the invisible Livepatch status one above). You can remove the App Indicator applet by editing the panel if you find them jarring.

Snap apps pinned to the COSMIC dock don’t show icons, and may not open when clicked. You can still use Snaps – just open them from the Applications picker or the Launcher.

All Linux apps run in COSMIC but won’t inherit the native look. COSMIC uses an Iced-based UI toolkit, not GTK or Qt. However, you can make GTK apps inherit some colours – it’s not flawless but (I chose a gaudy colour to illustrate) it can be done:

How? No foo; go to Settings > Desktop > Appearance and scroll to the bottom of the window. Click Icons and toolkit themeing and slide the Apply current theme to GNOME apps toggle on.

No doubt there may be other quirks compared to running a “vanilla” instance on Pop!_OS, but the fact it runs well (including the Lock Screen) is all credit to System76 for designing their desktop to be distro and setup agnostic — it even runs on BeOS now!

How to Revert to Stock Ubuntu

As this PPA may replaces some critical components, uninstalling the cosmic-session package will not restore things back to an original state. You will still be using whatever upgraded versions the PPA gave you.

To roll back the changes fully, you need to use ppa-purge. This is a command-line tool that will remove the PPA and “downgrade” the system packages back to the official versions carried in the Ubuntu ‘noble’ repositories.

Install PPA Purge by running this command in your terminal:

sudo apt install ppa-purge

Then run this command to jettison the COSMIC PPA (if you’re on Ubuntu):

sudo ppa-purge ppa:hepp3n/cosmic-epoch

Once the process completes, a reboot is recommended. This will ensure the system is running on the official LTS graphics stack.

Important

Any issues you encounter using COSMIC on Ubuntu should, in the first instance, be reported to the PPA maintainer and not upstream to System76 as they don’t maintain this PPA or provide support for it.