Broken apt update?

Accelerated Computing DGX Spark / GB10 User Forum DGX Spark / GB10
1

when I run apt update, I see the following output:

root@spark:~# apt update

(...)
                                          
Err:5 https://workbench.download.nvidia.com/stable/linux/debian default InRelease                                      
  The following signatures were invalid: EXPKEYSIG CD63F8B21266DE3C svc-workbench <svc-workbench@nvidia.com>

(...)

28 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://workbench.download.nvidia.com/stable/linux/debian default InRelease: The following signatures were invalid: EXPKEYSIG CD63F8B21266DE3C svc-workbench <svc-workbench@nvidia.com>
W: Failed to fetch https://workbench.download.nvidia.com/stable/linux/debian/dists/default/InRelease  The following signatures were invalid: EXPKEYSIG CD63F8B21266DE3C svc-workbench <svc-workbench@nvidia.com>
W: Some index files failed to download. They have been ignored, or old ones used instead.

have I damaged my apt sources somehow?

2

This is a known issue, there are details and a workaround posted here:

3

Please reference DGX Spark apt update failure (EXPKEYSIG)

4

The fix for Ubuntu repo signature invalid: EXPKEYSIG CD63F8B21266DE3C svc-workbench

sudo apt update (still see the error)
sudo apt full-upgrade (installs a new key)
sudo apt update (no error)

5

However, I have encountered a new problem now, about canonical-nvidia/vulkan-packages-nv-desktop. Can you fix it?

Err:18 https://snapshot.ppa.launchpadcontent.net/canonical-nvidia/vulkan-packages-nv-desktop/ubuntu noble/main arm64 Packages
File has unexpected size (5928 != 5920). Mirror sync in progress? [IP: 185.125.189.37 443]
Hashes of expected file:

  • Filesize:5920 [weak]
  • SHA256:1e1e5c62cabcd1eb53acdc7c62b3014843a2c75be84ecbc66c801438dc00af51
  • SHA1:68901986ad2669b5f6d2c9be617a00a7f3d12078 [weak]
  • MD5Sum:0d2d7687ad0396cf5ccb5c5a8065d754 [weak]
    Release file created at: Wed, 10 Dec 2025 11:42:25 +0000
6

I hit the same thing, looks like an error on the package metadata update. There’s not a CDN reporting that I can find for this repo, so I put an issue on the CUDA CDN repository to see if that tips off the right team at NVIDIA:

https://github.com/NVIDIA/cuda-repo-management/issues/33

7

Thanks, today it seems fixed. Merry Christmas!

8

Yep - probably @kmittman saving the day - Merry Christmas!

9

Fixed after apt full-upgrade. Merry Christmas!