Failed to build: Error installing snap 'cups' from channel 'latest/stable'

The Inkscape master build started failing a few weeks ago although we did not change the snapcraft configuration.

https://launchpad.net/~ted/+snap/inkscape-master

https://launchpadlibrarian.net/785387854/buildlog_snap_ubuntu_noble_arm64_inkscape-master_BUILDING.txt.gz

Installing build-snaps
Error installing snap 'cups' from channel 'latest/stable'.
Full execution log: '/root/.local/state/snapcraft/log/snapcraft-20250330-065843.265165.log'
Build failed

I get the error only in the launchpad builder, not in my Ubuntu 24.04 VM.

How can I debug and solve this issue?

By the way, here is the snapcraft.yaml (For whatever reason, new users can only add two links to a post :frowning: ) https://gitlab.com/inkscape/inkscape/-/blob/master/snap/snapcraft.yaml

Snapcraft is calling snap install ... to install build-snaps and Snapcraft hasn’t changed this code in years, so I’m not sure where the problem is. It’s unfortunate that snapcraft doesn’t display the stderr here.

Do you know exactly when this started failing?

There are not many easy ways to debug something that only fails on Launchpad, but one way is to remove the keys related to foo-install-cups and install the cups snap in an override-pull script. This may give you some informative error output.

Thanks for your help. I get the following error message:


:: + snap install cups
:: error: cannot perform the following tasks:
:: - Setup snap "cups" (1085) security profiles (cannot setup udev for snap "cups": cannot reload udev rules: exit status 1
:: udev output:
:: Failed to send reload request: No such file or directory
:: )

https://launchpadlibrarian.net/788967964/buildlog_snap_ubuntu_noble_amd64_inkscape-test_BUILDING.txt.gz

Looks like this is bug Bug #1712808 “udev interface fails in privileged containers” : Bugs : snapd that is fixed in snapd 2.68.3. Workaround for now: In the launchpad .net snap package configuration, use latest/candidate as snapd version. In the future this workaround should be changed to use the latest/stable version once the stable version of snapd https://snapcraft.io/snapd is >= 2.68.3.