[Merge] ~rmartin013/livecd-rootfs:ubuntu/jammy into livecd-rootfs:ubuntu/jammy

[Loïc Minier]

I tried to do a build from oracular to refresh my mind on how this works in master before looking at this backport; I intended to build a local image like this:

sudo apt install livecd-rootfs
mkdir build
cd build

rm -rf auto local config
rm -f livecd.*.model-assertion
mkdir -p auto
for s in config build clean; do ln -s /usr/share/livecd-rootfs/live-build/auto/$s auto/; done
lb clean --purge
export PROJECT=ubuntu-core ARCH=arm64 SUBARCH=tegra-igx SUITE=jammy IMAGEFORMAT=ubuntu-image CHANNEL=edge
lb config
sudo -E lb build

But at the lb config step, I get:
[2024-06-21 15:45:24] lb_config 
P: Executing auto/config script.
Building on oracular.lxd
Configured ubuntu-image for the following model assertion:
----------------------------------------------------------


Which suggests the model isn't setup properly.

Reading the code, it seems livecd-rootfs can only build UC24 images. But first, I tried to see if I could download the models locally; Noah told me these were the supported models: ubuntu-core-22-tegra-igx and ubuntu-core-22-tegra-igx-{edge,beta,candidate}; indeed this works:
env SNAPPY_STORE_NO_CDN=1 snap known --remote model series=16 model=ubuntu-core-22-tegra-igx-edge brand-id=canonical

After forcing UC22, I'm getting this during build:
[2024-06-21 16:17:28] lb_build 
P: Executing auto/build script.
2024-06-21T16:17:33Z INFO Waiting for automatic snapd restart...
ubuntu-image 3.4+snap1 from Canonical** installed
[0] prepare_image
WARNING: proceeding to download snaps ignoring validations, this default will change in the future. For now use --validation=enforce for validations to be taken into account, pass instead --validation=ignore to preserve current behavior going forward
Error: Error preparing image: cannot override channels, add devmode snaps, local snaps, or extra snaps with a model of grade higher than dangerous

I'm not sure how that's supposed to work, but dropping the extra-snaps, I can run this by hand instead of lb build, and I get a successful build:
sudo /snap/bin/ubuntu-image snap --snap=console-conf -O output livecd.ubuntu-core-tegra-igx.model-assertion
-- 
https://code.launchpad.net/~rmartin013/livecd-rootfs/+git/livecd-rootfs/+merge/466187
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