In the summer of even years, we upgrade all clients to the latest LTS version of Ubuntu. Below are some changes associate with the summer 2026 upgrade to Ubuntu 26.04 (Resolute Raccoon).

Returning users may need to review the following sections and update local configurations.

  • XFCE panels

  • CUDA/GPU drivers for AI/ML work

  • Python virtual environments

If you find a package is missing or broken, or you encounter any other issues not covered here, please report it sysadmins@cs.

XFCE

XFCE is the default graphical desktop environment for CS clients. For returning users, the upgrades may result in some application icons being modified or missing. In most cases, we recommend using the fix_xfce script to install a sensible default set of icons and panels for the new version of Ubuntu. To run this script, you must be logged out of your XFCE session. You can either connect to the CS network remotely via SSH on you personal device or switch to a console session on the client machine using Ctrl-Alt-F1. Once logged in, run the fix_xfce script and follow the prompts. It is OK to allow the script to remove and replace existing panels and icons it suggests.

If you are logged in to the console session, locally, exit the session by typing exit and then switch back to the graphical session using Ctrl-Alt-F7. You should now see the new XFCE panels and icons.

CUDA/GPU drivers for AI/ML/Graphics work

The majority of CS clients have NVIDIA graphics cards and can use CUDA for AI/ML work. Driver and CUDA upgrades may require you to change environment variables or update your virtual environments.

The default CUDA version is 13.2 with NVIDIA driver version 595. CUDA 12.5 is also installed for Tensorflow applications. Older versions of CUDA may be removed during fall 2026. If you are having trouble finding CUDA in your builds, consider setting the following environment variables in your build or ~/.bashrc file:

export PATH=/usr/local/cuda/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/cuda/lib64:/usr/local/lib/$LD_LIBRARY_PATH

No graphics hosts

A small number (~15) of machines do not have NVIDIA graphics cards. Theses machine should have a "No NVIDIA" sticker on the machine. These machines can still do general CS work, but may not be suitable for AI/ML or graphics work. If you are unsure if your machine has a NVIDIA graphics card, please run the following command in a terminal window:

lspci | grep -i vga

NVIDIA graphics cards will be listed as NVIDIA Corporation in the output. If you do not see NVIDIA in the output, you will not be able to use CUDA or GPU accelerated applications.

Python virtual environments

The default Python version is 3.14.4. If you have created virtual environments for your work, you may need to update them to use the new version of Python.

Python 3.13 is also installed for Tensorflow applications. Python 3.12 is also installed for legacy applications to match the version of Python used in the previous LTS release.

Please port you applications to Python3.14.

The python command is python3 in Ubuntu 26.04. If you have scripts that use the python command, please update them to use python3.

Clients running Ubuntu 24.04

If you find that something is broken on a 26.04 client that was working in Spring 2026, a few clients in second floor overflow labs (224, 226, and 228) have been held back from the upgrade and are still running Ubuntu 24.04 (Noble Numbat). These machines should have a label of "old OS" and should only be used to diagnose issues with the new Ubuntu 26.04 clients. Unless we continue to need these old clients for testing, they will be upgraded to Ubuntu 26.04 over fall break in October 2026.

Clients running 24.04:

  • M224: all clients osprey, saffron, olive, elderberry

  • M226: molasses, orange

  • M228: fischoeder, gayle, marshmallow, zeke

Miscellaneous Updates

python3

The python command is python3 in Ubuntu 26.04. If you have scripts that use the python command, please update them to use python3. If there is consensus, we can install the python-is-python3 package to alias python to python3. python worked on Ubuntu 24.04, but does not currently work on Ubuntu 26.04.

evince → papers

Evince PDF thumbnails are broken. papers is the recommended replacement PDF viewer.

Miscellaneous Issues/Known Bugs

Several packages have been marked as deprecated and removed from the base install. If you find something missing that you still need, please report it to sysadmins@cs. It is relatively easy to install additional packages that are available in the Ubuntu or third-party repositories.

xscreensaver/user switching

If you lock the screen and then either select the new login button or swap to a console session, then back to the graphical session, you may find that the screen is locked and you cannot unlock it. If this happens too often, you may not be able to create new graphical session logins. You can use Ctrl-Alt-Backspace to restart the display manager. We are looking into ways to fix this issue.

who and wtmp

The who command to see who is logged in is deprecated and likely to return a blank message. Use w instead. Ubuntu 26.04 transitioned to a modern wtmpdb logging system, phasing out the legacy utmp and wtmp files that the classic who tool relies on to display logged-in users.

Users of the attendance scripts for 21,31,and 35 labs/ninja sessions may need to check that their scripts work properly with the new wtmpdb system.

xfdesktop

this seems to be resolved as of mid August 2026. Please contact sysadmins@cs if you still see this problem.

When logging into a different machine using XFCE, you may get a xfdesktop popup asking if you would like to "assign an existing desktop icon layout" to the current monitor. You can safely ignore this message and close the window. Over time, this list of monitor configs will grow. Changes are saved in ~/.config/xfce4/desktop/icons.screen0.yml. We are looking into ways disable the popup and use a default layout for most monitors.