Mattermost Desktop repository install on 24.04 LTS "noble"

The installation instruction for the Mattermost Desktop Client don’t work for (K)Ubuntu 24.04 LTS “noble”.

Screenshot from: Install the Mattermost desktop app - Mattermost documentation

One issue is that the second half of the piped command, sudo bash only work if the shell is already authorized for shell. So if you did a sudo apt update (or any other sudo command) before, it will work, if not it will stall, the sudo password request might not be immediately obvious.

Once this hurdle has been overcome, you will still get an error,

Err:15 stable InRelease                       
  The following signatures were invalid: EXPKEYSIG F8F2C31744774B28 Mattermost Build <>

According to this forum post It seems the command is truncated and actually it should be curl -o- | sudo bash -s mattermost but this fails for 24.04 with the ERROR: Unsupported ubuntu release: "noble"

Will the invalid signature be fixed and will there be an release for 24.04 LTS anytime soon?

@mxa I’ve opened an internal case to investigate and resolve.

Hello @mxa ! I can confirm our repository doesn’t support Ubuntu 24.04 yet, but we plan to work on it very soon.

Regarding the signing key, it has been renewed recently. The setup script should’ve downloaded the new one automatically on a supported OS, but since it was run on Ubuntu 24.04 that step was skipped. I’ll let you know as soon as we add support for Ubuntu Noble.

edit: clarified that it’s only the repository that’s not working, not the desktop app itself

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Workaround for the issue is to use the binary provided here, or the .deb files or AppImage files from here.

Hello @mxa, thank you for all the feedback! I had a chance to test the Desktop installation instructions, and I’ve verified that they actually work on Ubuntu 24.04 already.

The reason it didn’t work for you is because you used the script, which sets up the repo for the Mattermost Server (this repo indeed doesn’t support Ubuntu Noble as of today).
The Desktop client setup instructions run the script instead, notice that setup and repo are swapped.

This actually confused me as well as I didn’t notice at first when reading your post, it’s definitely something we’ll improve in the near future as we work on other repository changes :+1:

As for the sudo command seemingly hanging if not run before in the same shell: as you mention it’s actually waiting for you to input the password, but it’s not visible due to curl’s output messing with the password prompt. We have updated the installation docs to improve on this, so that curl is silent unless there’s an error.

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